NEWS.md

ggplot2 (development version)

• Missing values from discrete palettes are no longer translated (@teunbrand, #5929).

• Fixed bug in facet_grid(margins = TRUE) when using expresssions (@teunbrand, #1864).

• geom_step() now supports the orientation argument (@teunbrand, #5936).

• position_dodge() and position_jitterdodge() now have a reverse argument (@teunbrand, #3610)

• coord_radial(r.axis.inside) can now take a numeric value to control placement of internally placed radius axes (@teunbrand, #5805).

• (internal) default labels are derived in ggplot_build() rather than in ggplot_add.Layer() (@teunbrand, #5894)

• An attempt is made to use a variable's label attribute as default label (@teunbrand, #4631)

• Themes gain an additional header_family argument to easily set the font for headers and titles (#5886).

• The plot.subtitle, plot.caption and plot.tag theme elements now inherit from the root text element instead of the title element (#5886).

• ggplot2 no longer imports {glue} (@teunbrand, #5986).

• geom_rect() can now derive the required corners positions from x/width or y/height parameterisation (@teunbrand, #5861).

• All position scales now use the same definition of x and y aesthetics. This lets uncommon aesthetics like xintercept expand scales as usual. (#3342, #4966, @teunbrand)

• Bare numeric values provided to Date or Datetime scales get inversely transformed (cast to Date/POSIXct) with a warning (@teunbrand).

• stat_bin() now accepts functions for argument breaks (@aijordan, #4561)

• (internal) The plot's layout now has a coord parameter that is used to prevent setting up identical panel parameters (#5427)

• (internal) rearranged the code of Facet$draw_panels() method (@teunbrand).

• geom_rug() prints a warning when na.rm = FALSE, as per documentation (@pn317, #5905)

• position_dodge(preserve = "single") now handles multi-row geoms better, such as geom_violin() (@teunbrand based on @clauswilke's work, #2801).

• position_jitterdodge() now dodges by group (@teunbrand, #3656)

• The arrow.fill parameter is now applied to more line-based functions: geom_path(), geom_line(), geom_step() geom_function(), line geometries in geom_sf() and element_line().

• Fixed bug where binned guides would keep out-of-bounds breaks (@teunbrand, #5870).

• The size of the draw_key_polygon() glyph now reflects the linewidth aesthetic (#4852).

• New function complete_theme() to replicate how themes are handled during plot building (#5801).

• Special getter and setter functions have been renamed for consistency, allowing for better tab-completion with get_*- and set_*-prefixes. The old names remain available for backward compatibility (@teunbrand, #5568).

  New name	Old name
  get_theme()	theme_get()
  set_theme()	theme_set()
  replace_theme()	theme_replace()
  update_theme()	theme_update()
  get_last_plot()	last_plot()
  get_layer_data()	layer_data()
  get_layer_grob()	layer_grob()
  get_panel_scales()	layer_scales()

• Discrete scales now support minor_breaks. This may only make sense in discrete position scales, where it affects the placement of minor ticks and minor gridlines (#5434).

• Discrete position scales now expose the palette argument, which can be used to customise spacings between levels (@teunbrand, #5770).

• The default se parameter in layers with geom = "smooth" will be TRUE when the data has ymin and ymax parameters and FALSE if these are absent. Note that this does not affect the default of geom_smooth() or stat_smooth() (@teunbrand, #5572).

• The bounded density option in stat_density() uses a wider range to prevent discontinuities (#5641).

• geom_raster() now falls back to rendering as geom_rect() when coordinates are not Cartesian (#5503).

• stat_ecdf() now has an optional weight aesthetic (@teunbrand, #5058).

• Position scales combined with coord_sf() can now use functions in the breaks argument. In addition, n.breaks works as intended and breaks = NULL removes grid lines and axes (@teunbrand, #4622).

• (Internal) Applying defaults in geom_sf() has moved from the internal sf_grob() to GeomSf$use_defaults() (@teunbrand).

• facet_wrap() has new options for the dir argument to more precisely control panel directions. Internally dir = "h" or dir = "v" is deprecated (@teunbrand, #5212).

• Prevented facet_wrap(..., drop = FALSE) from throwing spurious errors when a character facetting variable contained NAs (@teunbrand, #5485).

• When facets coerce the faceting variables to factors, the 'ordered' class is dropped (@teunbrand, #5666).

• geom_curve() now appropriately removes missing data instead of throwing errors (@teunbrand, #5831).

• update_geom_defaults() and update_stat_defaults() have a reset mechanism when using new = NULL and invisible return the previous defaults (#4993).

• Fixed regression in axes where breaks = NULL caused the axes to disappear instead of just rendering the axis line (@teunbrand, #5816).

• geom_point() can be dodged vertically by using position_dodge(..., orientation = "y") (@teunbrand, #5809).

• Fixed bug where na.value was incorrectly mapped to non-NA values (@teunbrand, #5756).

• Fixed bug in guide_custom() that would throw error with theme_void() (@teunbrand, #5856).

• New helper function gg_par() to translate ggplot2's interpretation of graphical parameters to {grid}'s interpretation (@teunbrand, #5866).

• scale_{x/y}_discrete() can now accept a sec.axis. It is recommended to only use dup_axis() to set custom breaks or labels, as discrete variables cannot be transformed (@teunbrand, #3171).

• stat_density() has the new computed variable: wdensity, which is calculated as the density times the sum of weights (@teunbrand, #4176).

• theme() gets new spacing and margins arguments that all other spacings and (non-text) margins inherit from (@teunbrand, #5622).

• geom_ribbon() can have varying fill or alpha in linear coordinate systems (@teunbrand, #4690).

• geom_tile() computes default widths and heights per panel instead of per layer (@teunbrand, #5740).

• The fill of the panel.border theme setting is ignored and forced to be transparent (#5782).

• stat_align() skips computation when there is only 1 group and therefore alignment is not necessary (#5788).

• position_stack() skips computation when all x values are unique and therefore stacking is not necessary (#5788).

• A new ggplot_build() S3 method for <ggplot_built> classes was added, which returns input unaltered (@teunbrand, #5800).

• width is implemented as aesthetic instead of parameter in geom_col() and geom_bar() (#3142).

• Fix a bug in position_jitterdodge() where different jitters would be applied to different position aesthetics of the same axis (@teunbrand, #5818).

• In stat_bin(), the default boundary is now chosen to better adhere to the nbin argument (@teunbrand, #5882, #5036)

• after_stat() and after_scale() throw warnings when the computed aesthetics are not of the correct length (#5901).

• guide_colourbar() now correctly hands off position and available_aes parameters downstream (@teunbrand, #5930)

• geom_hline() and geom_vline() now have position argument (@yutannihilation, #4285).

• New function get_strip_labels() to retrieve facet labels (@teunbrand, #4979)

• Fixed bug in position_dodge2()'s identification of range overlaps (@teunbrand, #5938, #4327).

• Fixed bug where empty discrete scales weren't recognised as such (@teunbrand, #5945).

ggplot2 3.5.1

This is a small release focusing on fixing regressions from 3.5.0 and documentation updates.

Bug fixes

• Fixed bug where discrete scales could not map aesthetics only consisting of NAs (#5623)
• Fixed spurious warnings from sec_axis() with breaks = NULL (#5713).
• Patterns and gradients are now also enabled in geom_sf() (@teunbrand, #5716).
• The default behaviour of resolution() has been reverted to pre-3.5.0 behaviour. Whether mapped discrete vectors should be treated as having resolution of 1 is controlled by the new discrete argument.
• Fixed bug in guide_bins() and guide_coloursteps() where discrete breaks, such as the levels produced by cut(), were ordered incorrectly (@teunbrand, #5757).

Improvements

• When facets coerce the faceting variables to factors, the 'ordered' class is dropped (@teunbrand, #5666).
• coord_map() and coord_polar() throw informative warnings when used with the guide system (#5707).
• When passing a function to stat_contour(breaks), that function is used to calculate the breaks even if bins and binwidth are missing (@teunbrand, #5686).
• geom_step() now supports lineend, linejoin and linemitre parameters (@teunbrand, #5705).
• Fixed performance loss when the .data pronoun is used in aes() (#5730).
• Facet evaluation is better at dealing with inherited errors (@teunbrand, #5670).
• stat_bin() deals with non-finite breaks better (@teunbrand, #5665).
• While axes in coord_radial() don't neatly fit the top/right/bottom/left organisation, specifying position = "top" or position = "right" in the scale will flip the placement of the radial axis (#5735)
• Theme elements that do not exist now throw warnings instead of errors (#5719).
• Fixed bug in coord_radial() where full circles were not treated as such (@teunbrand, #5750).
• When legends detect the presence of values in a layer, NA is now detected if the data contains values outside the given breaks (@teunbrand, #5749).
• annotate() now warns about stat or position arguments (@teunbrand, #5151)
• guide_coloursteps(even.steps = FALSE) now works with discrete data that has been formatted by cut() (@teunbrand, #3877).

ggplot2 3.5.0

This is a minor release that turned out quite beefy. It is focused on overhauling the guide system: the system responsible for displaying information from scales in the guise of axes and legends. As part of that overhaul, new guides have been implemented and existing guides have been refined. The look and feel of guides has been mostly preserved, but their internals and styling options have changed drastically.

Briefly summarising other highlights, we also welcome coord_radial() as a successor of coord_polar(). Initial support for newer graphical features, such as pattern fills has been added. The API has changed how I()/<AsIs> vectors interact with the scale system, namely: not at all.

Breaking changes

• The guide system. As a whole. See 'new features' for more information. While the S3 guide generics are still in place, the S3 methods for guide_train(), guide_merge(), guide_geom(), guide_transform(), guide_gengrob() have been superseded by the respective ggproto methods. In practice, this will mean that NextMethod() or sub-classing ggplot2's guides with the S3 system will no longer work.

• By default, guide_legend() now only draws a key glyph for a layer when the value is in the layer's data. To revert to the old behaviour, you can still set show.legend = c({aesthetic} = TRUE) (@teunbrand, #3648).

• In the scale_{colour/fill}_gradient2() and scale_{colour/fill}_steps2() functions, the midpoint argument is transformed by the scale transformation (#3198).

• The legend.key theme element is set to inherit from the panel.background theme element. The default themes no longer set the legend.key element. This causes a visual change with the default theme_gray() (#5549).

• The scale_name argument in continuous_scale(), discrete_scale() and binned_scale() is soft-deprecated. If you have implemented custom scales, be advised to double-check that unnamed arguments ends up where they should (@teunbrand, #1312).

• The legend.text.align and legend.title.align arguments in theme() are deprecated. The hjust setting of the legend.text and legend.title elements continues to fulfill the role of text alignment (@teunbrand, #5347).

• 'lines' units in geom_label(), often used in the label.padding argument, are now are relative to the text size. This causes a visual change, but fixes a misalignment issue between the textbox and text (@teunbrand, #4753)

• coord_flip() has been marked as superseded. The recommended alternative is to swap the x and y aesthetic and/or using the orientation argument in a layer (@teunbrand, #5130).

• The trans argument in scales and secondary axes has been renamed to transform. The trans argument itself is deprecated. To access the transformation from the scale, a new get_transformation() method is added to Scale-classes (#5558).

• Providing a numeric vector to theme(legend.position) has been deprecated. To set the default legend position inside the plot use theme(legend.position = "inside", legend.position.inside = c(...)) instead.

New features

• Plot scales now ignore AsIs objects constructed with I(x), instead of invoking the identity scale. This allows these columns to co-exist with other layers that need a non-identity scale for the same aesthetic. Also, it makes it easy to specify relative positions (@teunbrand, #5142).

• The fill aesthetic in many geoms now accepts grid's patterns and gradients. For developers of layer extensions, this feature can be enabled by switching from fill = alpha(fill, alpha) to fill = fill_alpha(fill, alpha) when providing fills to grid::gpar() (@teunbrand, #3997).

• New function check_device() for testing the availability of advanced graphics features introduced in R 4.1.0 onward (@teunbrand, #5332).

• coord_radial() is a successor to coord_polar() with more customisation options. coord_radial() can:

  • integrate with the new guide system via a dedicated guide_axis_theta() to display the angle coordinate.
  • in addition to drawing full circles, also draw circle sectors by using the end argument.
  • avoid data vanishing in the center of the plot by setting the donut argument.
  • adjust the angle aesthetic of layers, such as geom_text(), to align with the coordinate system using the rotate_angle argument.

The guide system

The guide system encompassing axes and legends, as the last remaining chunk of ggplot2, has been rewritten to use the <ggproto> system instead of the S3 system. This change was a necessary step to officially break open the guide system for extension package developers. The axes and legends now inherit from a <Guide> class, which makes them extensible in the same manner as geoms, stats, facets and coords (#3329, @teunbrand)

• The most user-facing change is that the styling of guides is rewired through the theme system. Guides now have a theme argument that can style individual guides, while theme() has gained additional arguments to style guides. Theme elements declared in the guide override theme elements set through the plot. The new theme elements for guides are: legend.key.spacing{.x/.y}, legend.frame, legend.axis.line, legend.ticks, legend.ticks.length, legend.text.position and legend.title.position. Previous style options in the arguments of guide_*() functions are soft-deprecated.

• Unfortunately, we could not fully preserve the function of pre-existing guide extensions written in the S3 system. A fallback for these old guides is encapsulated in the <GuideOld> class, which calls the old S3 generics. The S3 methods have been removed as part of cleaning up, so the old guides will still work if the S3 methods are reimplemented, but we encourage to switch to the new system (#2728).

• The order argument of guides now strictly needs to be a length-1 integer (#4958).

Axes

• New guide_axis_stack() to combine other axis guides on top of one another.

• New guide_axis_theta() to draw an axis in a circular arc in coord_radial(). The guide can be controlled by adding guides(theta = guide_axis_theta(...)) to a plot.

• New guide_axis_logticks() can be used to draw logarithmic tick marks as an axis. It supersedes the annotation_logticks() function (@teunbrand, #5325).

• guide_axis() gains a minor.ticks argument to draw minor ticks (#4387).

• guide_axis() gains a cap argument that can be used to trim the axis line to extreme breaks (#4907).

• Primary axis titles are now placed at the primary guide, so that guides(x = guide_axis(position = "top")) will display the title at the top by default (#4650).

• The default vjust for the axis.title.y.right element is now 1 instead of 0.

• Unknown secondary axis guide positions are now inferred as the opposite of the primary axis guide when the latter has a known position (#4650).

Legends

• New guide_custom() function for drawing custom graphical objects (grobs) unrelated to scales in legend positions (#5416).

• All legends have acquired a position argument, that allows individual guides to deviate from the legend.position set in the theme() function. This means that legends can now be placed at multiple sides of the plot (#5488).

• The spacing between legend keys and their labels, in addition to legends and their titles, is now controlled by the text's margin setting. Not specifying margins will automatically add appropriate text margins. To control the spacing within a legend between keys, the new legend.key.spacing.{x/y} argument can be used in theme(). This leaves the legend.spacing theme setting dedicated to solely controlling the spacing between different guides (#5455).

• guide_colourbar() and guide_coloursteps() gain an alpha argument to set the transparency of the bar (#5085).

• New display argument in guide_colourbar() supplants the raster argument. In R 4.1.0 and above, display = "gradient" will draw a gradient.

• Legend keys that can draw arrows have their size adjusted for arrows.

• When legend titles are larger than the legend, title justification extends to the placement of keys and labels (#1903).

• Glyph drawing functions of the draw_key_*() family can now set "width" and "height" attributes (in centimetres) to the produced keys to control their displayed size in the legend.

• coord_sf() now uses customisable guides provided in the scales or guides() function (@teunbrand).

Improvements

• guide_coloursteps(even.steps = FALSE) now draws one rectangle per interval instead of many small ones (#5481).

• draw_key_label() now better reflects the appearance of labels (#5561).

• position_stack() no longer silently removes missing data, which is now handled by the geom instead of position (#3532).

• The minor_breaks function argument in scales can now also take a function with two arguments: the scale's limits and the scale's major breaks (#3583).

• Failing to fit or predict in stat_smooth() now gives a warning and omits the failed group, instead of throwing an error (@teunbrand, #5352).

• labeller() now handles unspecified entries from lookup tables (@92amartins, #4599).

• fortify.default() now accepts a data-frame-like object granted the object exhibits healthy dim(), colnames(), and as.data.frame() behaviours (@hpages, #5390).

• geom_violin() gains a bounds argument analogous to geom_density()s (@eliocamp, #5493).

• To apply dodging more consistently in violin plots, stat_ydensity() now has a drop argument to keep or discard groups with 1 observation.

• geom_boxplot() gains a new argument, staplewidth that can draw staples at the ends of whiskers (@teunbrand, #5126)

• geom_boxplot() gains an outliers argument to switch outliers on or off, in a manner that does affects the scale range. For hiding outliers that does not affect the scale range, you can continue to use outlier.shape = NA (@teunbrand, #4892).

• Nicer error messages for xlim/ylim arguments in coord-* functions (@92amartins, #4601, #5297).

• You can now omit either xend or yend from geom_segment() as only one of these is now required. If one is missing, it will be filled from the x and y aesthetics respectively. This makes drawing horizontal or vertical segments a little bit more convenient (@teunbrand, #5140).

• When geom_path() has aesthetics varying within groups, the arrow() is applied to groups instead of individual segments (@teunbrand, #4935).

• geom_text() and geom_label() gained a size.unit parameter that set the text size to millimetres, points, centimetres, inches or picas (@teunbrand, #3799).

• geom_label() now uses the angle aesthetic (@teunbrand, #2785)

• The label.padding argument in geom_label() now supports inputs created with the margin() function (#5030).

• ScaleContinuous$get_breaks() now only calls scales::zero_range() on limits in transformed space, rather than in data space (#5304).

• Scales throw more informative messages (@teunbrand, #4185, #4258)

• scale_*_manual() with a named values argument now emits a warning when none of those names match the values found in the data (@teunbrand, #5298).

• The name argument in most scales is now explicitly the first argument (#5535)

• The translate_shape_string() internal function is now exported for use in extensions of point layers (@teunbrand, #5191).

• To improve width calculation in bar plots with empty factor levels, resolution() considers mapped_discrete values as having resolution 1 (@teunbrand, #5211)

• In theme(), some elements can be specified with rel() to inherit from unit-class objects in a relative fashion (@teunbrand, #3951).

• theme() now supports splicing a list of arguments (#5542).

• In the theme element hierarchy, parent elements that are a strict subclass of child elements now confer their subclass upon the children (#5457).

• New plot.tag.location in theme() can control placement of the plot tag in the "margin", "plot" or the new "panel" option (#4297).

• coord_munch() can now close polygon shapes (@teunbrand, #3271)

• Aesthetics listed in geom_*() and stat_*() layers now point to relevant documentation (@teunbrand, #5123).

• The new argument axes in facet_grid() and facet_wrap() controls the display of axes at interior panel positions. Additionally, the axis.labels argument can be used to only draw tick marks or fully labelled axes (@teunbrand, #4064).

• coord_polar() can have free scales in facets (@teunbrand, #2815).

• The get_guide_data() function can be used to extract position and label information from the plot (#5004).

• Improve performance of layers without positional scales (@zeehio, #4990)

• More informative error for mismatched direction/theme(legend.direction = ...) arguments (#4364, #4930).

Bug fixes

• Fixed regression in guide_legend() where the linewidth key size wasn't adapted to the width of the lines (#5160).

• In guide_bins(), the title no longer arbitrarily becomes offset from the guide when it has long labels.

• guide_colourbar() and guide_coloursteps() merge properly when one of the aesthetics is dropped (#5324).

• When using geom_dotplot(binaxis = "x") with a discrete y-variable, dots are now stacked from the y-position rather than from 0 (@teunbrand, #5462)

• stat_count() treats x as unique in the same manner unique() does (#4609).

• The plot's title, subtitle and caption now obey horizontal text margins (#5533).

• Contour functions will not fail when options("OutDec") is not . (@eliocamp, #5555).

• Lines where linewidth = NA are now dropped in geom_sf() (#5204).

• ggsave() no longer sometimes creates new directories, which is now controlled by the new create.dir argument (#5489).

• Legend titles no longer take up space if they've been removed by setting legend.title = element_blank() (@teunbrand, #3587).

• resolution() has a small tolerance, preventing spuriously small resolutions due to rounding errors (@teunbrand, #2516).

• stage() now works correctly, even with aesthetics that do not have scales (#5408)

• stat_ydensity() with incomplete groups calculates the default width parameter more stably (@teunbrand, #5396)

• The size argument in annotation_logticks() has been deprecated in favour of the linewidth argument (#5292).

• Binned scales now treat NAs in limits the same way continuous scales do (#5355).

• Binned scales work better with trans = "reverse" (#5355).

• Integers are once again valid input to theme arguments that expect numeric input (@teunbrand, #5369)

• Legends in scale_*_manual() can show NA values again when the values is a named vector (@teunbrand, #5214, #5286).

• Fixed bug in coord_sf() where graticule lines didn't obey panel.grid.major's linewidth setting (@teunbrand, #5179)

• Fixed bug in annotation_logticks() when no suitable tick positions could be found (@teunbrand, #5248).

• The default width of geom_bar() is now based on panel-wise resolution of the data, rather than global resolution (@teunbrand, #4336).

• stat_align() is now applied per panel instead of globally, preventing issues when facets have different ranges (@teunbrand, #5227).

• A stacking bug in stat_align() was fixed (@teunbrand, #5176).

• stat_contour() and stat_contour_filled() now warn about and remove duplicated coordinates (@teunbrand, #5215).

• guide_coloursteps() and guide_bins() sort breaks (#5152).

Internal changes

• The ScaleContinuous$get_breaks() method no longer censors the computed breaks.

• The ggplot object now contains $layout which points to the Layout ggproto object and will be used by the ggplot_build.ggplot method. This was exposed so that package developers may extend the behaviour of the Layout ggproto object without needing to develop an entirely new ggplot_build method (@jtlandis, #5077).

• Guide building is now part of ggplot_build() instead of ggplot_gtable() to allow guides to observe unmapped data (#5483).

• The titleGrob() function has been refactored to be faster and less complicated.

• The scales_*() functions related to managing the <ScalesList> class have been implemented as methods in the <ScalesList> class, rather than stray functions (#1310).

ggplot2 3.4.4

This hotfix release adapts to a change in r-devel's base::is.atomic() and the upcoming retirement of maptools.

• fortify() for sp objects (e.g., SpatialPolygonsDataFrame) is now deprecated and will be removed soon in support of the upcoming retirement of rgdal, rgeos, and maptools. In advance of the whole removal, fortify(<SpatialPolygonsDataFrame>, region = ...) no longer works as of this version (@yutannihilation, #5244).

ggplot2 3.4.3

This hotfix release addresses a version comparison change in r-devel. There are no user-facing or breaking changes.

ggplot2 3.4.2

This is a hotfix release anticipating changes in r-devel, but folds in upkeep changes and a few bug fixes as well.

Minor improvements

• Various type checks and their messages have been standardised (@teunbrand, #4834).

• ggplot2 now uses scales::DiscreteRange and scales::ContinuousRange, which are available to write scale extensions from scratch (@teunbrand, #2710).

• The layer_data(), layer_scales() and layer_grob() now have the default plot = last_plot() (@teunbrand, #5166).

• The datetime_scale() scale constructor is now exported for use in extension packages (@teunbrand, #4701).

Bug fixes

• update_geom_defaults() and update_stat_defaults() now return properly classed objects and have updated docs (@dkahle, #5146).

• For the purposes of checking required or non-missing aesthetics, character vectors are no longer considered non-finite (@teunbrand, @4284).

• annotation_logticks() skips drawing ticks when the scale range is non-finite instead of throwing an error (@teunbrand, #5229).

• Fixed spurious warnings when the weight was used in stat_bin_2d(), stat_boxplot(), stat_contour(), stat_bin_hex() and stat_quantile() (@teunbrand, #5216).

• To prevent changing the plotting order, stat_sf() is now computed per panel instead of per group (@teunbrand, #4340).

• Fixed bug in coord_sf() where graticule lines didn't obey panel.grid.major's linewidth setting (@teunbrand, #5179).

• geom_text() drops observations where angle = NA instead of throwing an error (@teunbrand, #2757).

ggplot2 3.4.1

This is a small release focusing on fixing regressions in the 3.4.0 release and minor polishes.

Breaking changes

• The computed variable y in stat_ecdf() has been superseded by ecdf to prevent incorrect scale transformations (@teunbrand, #5113 and #5112).

New features

• Added scale_linewidth_manual() and scale_linewidth_identity() to support the linewidth aesthetic (@teunbrand, #5050).

• ggsave() warns when multiple filenames are given, and only writes to the first file (@teunbrand, #5114).

Bug fixes

• Fixed a regression in geom_hex() where aesthetics were replicated across bins (@thomasp85, #5037 and #5044).

• Using two ordered factors as facetting variables in facet_grid(..., as.table = FALSE) now throws a warning instead of an error (@teunbrand, #5109).

• Fixed misbehaviour of draw_key_boxplot() and draw_key_crossbar() with skewed key aspect ratio (@teunbrand, #5082).

• Fixed spurious warning when weight aesthetic was used in stat_smooth() (@teunbrand based on @clauswilke's suggestion, #5053).

• The lwd alias is now correctly replaced by linewidth instead of size (@teunbrand based on @clauswilke's suggestion #5051).

• Fixed a regression in Coord$train_panel_guides() where names of guides were dropped (@maxsutton, #5063).

In binned scales:

• Automatic breaks should no longer be out-of-bounds, and automatic limits are adjusted to include breaks (@teunbrand, #5082).

• Zero-range limits no longer throw an error and are treated akin to continuous scales with zero-range limits (@teunbrand, #5066).

• The trans = "date" and trans = "time" transformations were made compatible (@teunbrand, #4217).

ggplot2 3.4.0

This is a minor release focusing on tightening up the internals and ironing out some inconsistencies in the API. The biggest change is the addition of the linewidth aesthetic that takes of sizing the width of any line from size. This change, while attempting to be as non-breaking as possible, has the potential to change the look of some of your plots.

Other notable changes is a complete redo of the error and warning messaging in ggplot2 using the cli package. Messaging is now better contextualised and it should be easier to identify which layer an error is coming from. Last, we have now made the switch to using the vctrs package internally which means that support for vctrs classes as variables should improve, along with some small gains in rendering speed.

Breaking changes

• A linewidth aesthetic has been introduced and supersedes the size aesthetic for scaling the width of lines in line based geoms. size will remain functioning but deprecated for these geoms and it is recommended to update all code to reflect the new aesthetic. For geoms that have both point sizing and linewidth sizing (geom_pointrange() and geom_sf) size now only refers to sizing of points which can leads to a visual change in old code (@thomasp85, #3672)

• The default line width for polygons in geom_sf() have been decreased to 0.2 to reflect that this is usually used for demarking borders where a thinner line is better suited. This change was made since we already induced a visual change in geom_sf() with the introduction of the linewidth aesthetic.

• The dot-dot notation (..var..) and stat(), which have been superseded by after_stat(), are now formally deprecated (@yutannihilation, #3693).

• qplot() is now formally deprecated (@yutannihilation, #3956).

• stage() now properly refers to the values without scale transformations for the stage of after_stat. If your code requires the scaled version of the values for some reason, you have to apply the same transformation by yourself, e.g. sqrt() for scale_{x,y}_sqrt() (@yutannihilation and @teunbrand, #4155).

• Use rlang::hash() instead of digest::digest(). This update may lead to changes in the automatic sorting of legends. In order to enforce a specific legend order use the order argument in the guide. (@thomasp85, #4458)

• referring to x in backquoted expressions with label_bquote() is no longer possible.

• The ticks.linewidth and frame.linewidth parameters of guide_colourbar() are now multiplied with .pt like elsewhere in ggplot2. It can cause visual changes when these arguments are not the defaults and these changes can be restored to their previous behaviour by adding / .pt (@teunbrand #4314).

• scale_*_viridis_b() now uses the full range of the viridis scales (@gregleleu, #4737)

New features

• geom_col() and geom_bar() gain a new just argument. This is set to 0.5 by default; use just = 0/just = 1 to place columns on the left/right of the axis breaks. (@wurli, #4899)

• geom_density() and stat_density() now support bounds argument to estimate density with boundary correction (@echasnovski, #4013).

• ggplot now checks during statistical transformations whether any data columns were dropped and warns about this. If stats intend to drop data columns they can declare them in the new field dropped_aes. (@clauswilke, #3250)

• ... supports rlang::list2 dynamic dots in all public functions. (@mone27, #4764)

• theme() now has a strip.clip argument, that can be set to "off" to prevent the clipping of strip text and background borders (@teunbrand, #4118)

• geom_contour() now accepts a function in the breaks argument (@eliocamp, #4652).

Minor improvements and bug fixes

• Fix a bug in position_jitter() where infinity values were dropped (@javlon, #4790).

• geom_linerange() now respects the na.rm argument (#4927, @thomasp85)

• Improve the support for guide_axis() on coord_trans() (@yutannihilation, #3959)

• Added stat_align() to align data without common x-coordinates prior to stacking. This is now the default stat for geom_area() (@thomasp85, #4850)

• Fix a bug in stat_contour_filled() where break value differences below a certain number of digits would cause the computations to fail (@thomasp85, #4874)

• Secondary axis ticks are now positioned more precisely, removing small visual artefacts with alignment between grid and ticks (@thomasp85, #3576)

• Improve stat_function documentation regarding xlim argument. (@92amartins, #4474)

• Fix various issues with how labels, breaks, limits, and show.limits interact in the different binning guides (@thomasp85, #4831)

• Automatic break calculation now squishes the scale limits to the domain of the transformation. This allows scale_{x/y}_sqrt() to find breaks at 0
  when appropriate (@teunbrand, #980).

• Using multiple modified aesthetics correctly will no longer trigger warnings. If used incorrectly, the warning will now report the duplicated aesthetic instead of NA (@teunbrand, #4707).

• aes() now supports the !!! operator in its first two arguments (#2675). Thanks to @yutannihilation and @teunbrand for draft implementations.

• Require rlang >= 1.0.0 (@billybarc, #4797)

• geom_violin() no longer issues "collapsing to unique 'x' values" warning (@bersbersbers, #4455)

• annotate() now documents unsupported geoms (geom_abline(), geom_hline() and geom_vline()), and warns when they are requested (@mikmart, #4719)

• presidential dataset now includes Trump's presidency (@bkmgit, #4703).

• position_stack() now works fully with geom_text() (@thomasp85, #4367)

• geom_tile() now correctly recognises missing data in xmin, xmax, ymin, and ymax (@thomasp85 and @sigmapi, #4495)

• geom_hex() will now use the binwidth from stat_bin_hex() if present, instead of deriving it (@thomasp85, #4580)

• geom_hex() now works on non-linear coordinate systems (@thomasp85)

• Fixed a bug throwing errors when trying to render an empty plot with secondary axes (@thomasp85, #4509)

• Axes are now added correctly in facet_wrap() when as.table = FALSE (@thomasp85, #4553)

• Better compatibility of custom device functions in ggsave() (@thomasp85, #4539)

• Binning scales are now more resilient to calculated limits that ends up being NaN after transformations (@thomasp85, #4510)

• Strip padding in facet_grid() is now only in effect if strip.placement = "outside" and an axis is present between the strip and the panel (@thomasp85, #4610)

• Aesthetics of length 1 are now recycled to 0 if the length of the data is 0 (@thomasp85, #4588)

• Setting size = NA will no longer cause guide_legend() to error (@thomasp85, #4559)

• Setting stroke to NA in geom_point() will no longer impair the sizing of the points (@thomasp85, #4624)

• stat_bin_2d() now correctly recognises the weight aesthetic (@thomasp85, #4646)

• All geoms now have consistent exposure of linejoin and lineend parameters, and the guide keys will now respect these settings (@thomasp85, #4653)

• geom_sf() now respects arrow parameter for lines (@jakeruss, #4659)

• Updated documentation for print.ggplot to reflect that it returns the original plot, not the result of ggplot_build(). (@r2evans, #4390)

• scale_*_manual() no longer displays extra legend keys, or changes their order, when a named values argument has more items than the data. To display all values on the legend instead, use scale_*_manual(values = vals, limits = names(vals)). (@teunbrand, @banfai, #4511, #4534)

• Updated documentation for geom_contour() to correctly reflect argument precedence between bins and binwidth. (@eliocamp, #4651)

• Dots in geom_dotplot() are now correctly aligned to the baseline when stackratio != 1 and stackdir != "up" (@mjskay, #4614)

• Key glyphs for geom_boxplot(), geom_crossbar(), geom_pointrange(), and geom_linerange() are now orientation-aware (@mjskay, #4732)

• Updated documentation for geom_smooth() to more clearly describe effects of the fullrange parameter (@thoolihan, #4399).

ggplot2 3.3.6

This is a very small release only applying an internal change to comply with R 4.2 and its deprecation of default.stringsAsFactors(). There are no user facing changes and no breaking changes.

ggplot2 3.3.5

This is a very small release focusing on fixing a couple of untenable issues that surfaced with the 3.3.4 release

• Revert changes made in #4434 (apply transform to intercept in geom_abline()) as it introduced undesirable issues far worse than the bug it fixed (@thomasp85, #4514)
• Fixes an issue in ggsave() when producing emf/wmf files (@yutannihilation, #4521)
• Warn when grDevices specific arguments are passed to ragg devices (@thomasp85, #4524)
• Fix an issue where coord_sf() was reporting that it is non-linear even when data is provided in projected coordinates (@clauswilke, #4527)

ggplot2 3.3.4

This is a larger patch release fixing a huge number of bugs and introduces a small selection of feature refinements.

Features

• Alt-text can now be added to a plot using the alt label, i.e + labs(alt = ...). Currently this alt text is not automatically propagated, but we plan to integrate into Shiny, RMarkdown, and other tools in the future. (@thomasp85, #4477)

• Add support for the BrailleR package for creating descriptions of the plot when rendered (@thomasp85, #4459)

• coord_sf() now has an argument default_crs that specifies the coordinate reference system (CRS) for non-sf layers and scale/coord limits. This argument defaults to NULL, which means non-sf layers are assumed to be in projected coordinates, as in prior ggplot2 versions. Setting default_crs = sf::st_crs(4326) provides a simple way to interpret x and y positions as longitude and latitude, regardless of the CRS used by coord_sf(). Authors of extension packages implementing stat_sf()-like functionality are encouraged to look at the source code of stat_sf()'s compute_group() function to see how to provide scale-limit hints to coord_sf() (@clauswilke, #3659).

• ggsave() now uses ragg to render raster output if ragg is available. It also handles custom devices that sets a default unit (e.g. ragg::agg_png) correctly (@thomasp85, #4388)

• ggsave() now returns the saved file location invisibly (#3379, @eliocamp). Note that, as a side effect, an unofficial hack <ggplot object> + ggsave() no longer works (#4513).

• The scale arguments limits, breaks, minor_breaks, labels, rescaler and oob now accept purrr style lambda notation (@teunbrand, #4427). The same is true for as_labeller() (and therefore also labeller()) (@netique, #4188).

• Manual scales now allow named vectors passed to values to contain fewer elements than existing in the data. Elements not present in values will be set to NA (@thomasp85, #3451)

• Date and datetime position scales support out-of-bounds (oob) arguments to control how limits affect data outside those limits (@teunbrand, #4199).

Fixes

• Fix a bug that after_stat() and after_scale() cannot refer to aesthetics if it's specified in the plot-global mapping (@yutannihilation, #4260).

• Fix bug in annotate_logticks() that would cause an error when used together with coord_flip() (@thomasp85, #3954)

• Fix a bug in geom_abline() that resulted in intercept not being subjected to the transformation of the y scale (@thomasp85, #3741)

• Extent the range of the line created by geom_abline() so that line ending is not visible for large linewidths (@thomasp85, #4024)

• Fix bug in geom_dotplot() where dots would be positioned wrong with stackgroups = TRUE (@thomasp85, #1745)

• Fix calculation of confidence interval for locfit smoothing in geom_smooth() (@topepo, #3806)

• Fix bug in geom_text() where "outward" and "inward" justification for some angle values was reversed (@aphalo, #4169, #4447)

• ggsave() now sets the default background to match the fill value of the plot.background theme element (@karawoo, #4057)

• It is now deprecated to specify guides(<scale> = FALSE) or scale_*(guide = FALSE) to remove a guide. Please use guides(<scale> = "none") or scale_*(guide = "none") instead (@yutannihilation, #4097)

• Fix a bug in guide_bins() where keys would disappear if the guide was reversed (@thomasp85, #4210)

• Fix bug in guide_coloursteps() that would repeat the terminal bins if the breaks coincided with the limits of the scale (@thomasp85, #4019)

• Make sure that default labels from default mappings doesn't overwrite default labels from explicit mappings (@thomasp85, #2406)

• Fix bug in labeller() where parsing was turned off if .multiline = FALSE (@thomasp85, #4084)

• Make sure label_bquote() has access to the calling environment when evaluating the labels (@thomasp85, #4141)

• Fix a bug in the layer implementation that introduced a new state after the first render which could lead to a different look when rendered the second time (@thomasp85, #4204)

• Fix a bug in legend justification where justification was lost of the legend dimensions exceeded the available size (@thomasp85, #3635)

• Fix a bug in position_dodge2() where NA values in thee data would cause an error (@thomasp85, #2905)

• Make sure position_jitter() creates the same jittering independent of whether it is called by name or with constructor (@thomasp85, #2507)

• Fix a bug in position_jitter() where different jitters would be applied to different position aesthetics of the same axis (@thomasp85, #2941)

• Fix a bug in qplot() when supplying c(NA, NA) as axis limits (@thomasp85, #4027)

• Remove cross-inheritance of default discrete colour/fill scales and check the type and aesthetic of function output if type is a function (@thomasp85, #4149)

• Fix bug in scale_[x|y]_date() where custom breaks functions that resulted in fractional dates would get misaligned (@thomasp85, #3965)

• Fix bug in scale_[x|y]_datetime() where a specified timezone would be ignored by the scale (@thomasp85, #4007)

• Fix issue in sec_axis() that would throw warnings in the absence of any secondary breaks (@thomasp85, #4368)

• stat_bin()'s computed variable width is now documented (#3522).

• stat_count() now computes width based on the full dataset instead of per group (@thomasp85, #2047)

• Extended stat_ecdf() to calculate the cdf from either x or y instead from y only (@jgjl, #4005)

• Fix a bug in stat_summary_bin() where one more than the requested number of bins would be created (@thomasp85, #3824)

• Only drop groups in stat_ydensity() when there are fewer than two data points and throw a warning (@andrewwbutler, #4111).

• Fixed a bug in strip assembly when theme has strip.text = element_blank() and plots are faceted with multi-layered strips (@teunbrand, #4384).

• Using theme(aspect.ratio = ...) together with free space in facet_grid() now correctly throws an error (@thomasp85, #3834)

• Fixed a bug in labeller() so that .default is passed to as_labeller() when labellers are specified by naming faceting variables. (@waltersom, #4031)

• Updated style for example code (@rjake, #4092)

• ggplot2 now requires R >= 3.3 (#4247).

• ggplot2 now uses rlang::check_installed() to check if a suggested package is installed, which will offer to install the package before continuing (#4375, @malcolmbarrett)

• Improved error with hint when piping a ggplot object into a facet function (#4379, @mitchelloharawild).

ggplot2 3.3.3

This is a small patch release mainly intended to address changes in R and CRAN. It further changes the licensing model of ggplot2 to an MIT license.

• Update the ggplot2 licence to an MIT license (#4231, #4232, #4233, and #4281)

• Use vdiffr conditionally so ggplot2 can be tested on systems without vdiffr

• Update tests to work with the new all.equal() defaults in R >4.0.3

• Fixed a bug that guide_bins() mistakenly ignore override.aes argument (@yutannihilation, #4085).

ggplot2 3.3.2

This is a small release focusing on fixing regressions introduced in 3.3.1.

• Added an outside option to annotation_logticks() that places tick marks outside of the plot bounds. (#3783, @kbodwin)

• annotation_raster() adds support for native rasters. For large rasters, native rasters render significantly faster than arrays (@kent37, #3388)

• Facet strips now have dedicated position-dependent theme elements (strip.text.x.top, strip.text.x.bottom, strip.text.y.left, strip.text.y.right) that inherit from strip.text.x and strip.text.y, respectively. As a consequence, some theme stylings now need to be applied to the position-dependent elements rather than to the parent elements. This change was already introduced in ggplot2 3.3.0 but not listed in the changelog. (@thomasp85, #3683)

• Facets now handle layers containing no data (@yutannihilation, #3853).

• A newly added geom geom_density_2d_filled() and associated stat stat_density_2d_filled() can draw filled density contours (@clauswilke, #3846).

• A newly added geom_function() is now recommended to use in conjunction with/instead of stat_function(). In addition, stat_function() now works with transformed y axes, e.g. scale_y_log10(), and in plots containing no other data or layers (@clauswilke, #3611, #3905, #3983).

• Fixed a bug in geom_sf() that caused problems with legend-type autodetection (@clauswilke, #3963).

• Support graphics devices that use the file argument instead of fileneame in ggsave() (@bwiernik, #3810)

• Default discrete color scales are now configurable through the options() of ggplot2.discrete.colour and ggplot2.discrete.fill. When set to a character vector of colour codes (or list of character vectors) with sufficient length, these colours are used for the default scale. See help(scale_colour_discrete) for more details and examples (@cpsievert, #3833).

• Default continuous colour scales (i.e., the options() ggplot2.continuous.colour and ggplot2.continuous.fill, which inform the type argument of scale_fill_continuous() and scale_colour_continuous()) now accept a function, which allows more control over these default continuous_scale()s (@cpsievert, #3827).

• A bug was fixed in stat_contour() when calculating breaks based on the bins argument (@clauswilke, #3879, #4004).

• Data columns can now contain Vector S4 objects, which are widely used in the Bioconductor project. (@teunbrand, #3837)

ggplot2 3.3.1

This is a small release with no code change. It removes all malicious links to a site that got hijacked from the readme and pkgdown site.

ggplot2 3.3.0

This is a minor release but does contain a range of substantial new features, along with the standard bug fixes. The release contains a few visual breaking changes, along with breaking changes for extension developers due to a shift in internal representation of the position scales and their axes. No user breaking changes are included.

This release also adds Dewey Dunnington (@paleolimbot) to the core team.

Breaking changes

There are no user-facing breaking changes, but a change in some internal representations that extension developers may have relied on, along with a few breaking visual changes which may cause visual tests in downstream packages to fail.

• The panel_params field in the Layout now contains a list of list of ViewScale objects, describing the trained coordinate system scales, instead of the list object used before. Any extensions that use this field will likely break, as will unit tests that checks aspects of this.

• element_text() now issues a warning when vectorized arguments are provided, as in colour = c("red", "green", "blue"). Such use is discouraged and not officially supported (@clauswilke, #3492).

• Changed theme_grey() setting for legend key so that it creates no border (NA) rather than drawing a white one. (@annennenne, #3180)

• geom_ribbon() now draws separate lines for the upper and lower intervals if colour is mapped. Similarly, geom_area() and geom_density() now draw the upper lines only in the same case by default. If you want old-style full stroking, use outline.type = "full" (@yutannihilation, #3503 / @thomasp85, #3708).

New features

• The evaluation time of aesthetics can now be controlled to a finer degree. after_stat() supersedes the use of stat() and ..var..-notation, and is joined by after_scale() to allow for mapping to scaled aesthetic values. Remapping of the same aesthetic is now supported with stage(), so you can map a data variable to a stat aesthetic, and remap the same aesthetic to something else after statistical transformation (@thomasp85, #3534)

• All coord_*() functions with xlim and ylim arguments now accept vectors with NA as a placeholder for the minimum or maximum value (e.g., ylim = c(0, NA) would zoom the y-axis from 0 to the maximum value observed in the data). This mimics the behaviour of the limits argument in continuous scale functions (@paleolimbot, #2907).

• Allowed reversing of discrete scales by re-writing get_limits() (@AnneLyng, #3115)

• All geoms and stats that had a direction (i.e. where the x and y axes had different interpretation), can now freely choose their direction, instead of relying on coord_flip(). The direction is deduced from the aesthetic mapping, but can also be specified directly with the new orientation argument (@thomasp85, #3506).

• Position guides can now be customized using the new guide_axis(), which can be passed to position scale_*() functions or via guides(). The new axis guide (guide_axis()) comes with arguments check.overlap (automatic removal of overlapping labels), angle (easy rotation of axis labels), and n.dodge (dodge labels into multiple rows/columns) (@paleolimbot, #3322).

• A new scale type has been added, that allows binning of aesthetics at the scale level. It has versions for both position and non-position aesthetics and comes with two new guides (guide_bins and guide_coloursteps) (@thomasp85, #3096)

• scale_x_continuous() and scale_y_continuous() gains an n.breaks argument guiding the number of automatic generated breaks (@thomasp85, #3102)

• Added stat_contour_filled() and geom_contour_filled(), which compute and draw filled contours of gridded data (@paleolimbot, #3044). geom_contour() and stat_contour() now use the isoband package to compute contour lines. The complete parameter (which was undocumented and has been unused for at least four years) was removed (@paleolimbot, #3044).

• Themes have gained two new parameters, plot.title.position and plot.caption.position, that can be used to customize how plot title/subtitle and plot caption are positioned relative to the overall plot (@clauswilke, #3252).

Extensions

• Geom now gains a setup_params() method in line with the other ggproto classes (@thomasp85, #3509)

• The newly added function register_theme_elements() now allows developers of extension packages to define their own new theme elements and place them into the ggplot2 element tree (@clauswilke, #2540).

Minor improvements and bug fixes

• coord_trans() now draws second axes and accepts xlim, ylim, and expand arguments to bring it up to feature parity with coord_cartesian(). The xtrans and ytrans arguments that were deprecated in version 1.0.1 in favour of x and y were removed (@paleolimbot, #2990).

• coord_trans() now calculates breaks using the expanded range (previously these were calculated using the unexpanded range, which resulted in differences between plots made with coord_trans() and those made with coord_cartesian()). The expansion for discrete axes in coord_trans() was also updated such that it behaves identically to that in coord_cartesian() (@paleolimbot, #3338).

• expand_scale() was deprecated in favour of expansion() for setting the expand argument of x and y scales (@paleolimbot).

• geom_abline(), geom_hline(), and geom_vline() now issue more informative warnings when supplied with set aesthetics (i.e., slope, intercept, yintercept, and/or xintercept) and mapped aesthetics (i.e., data and/or mapping).

• Fix a bug in geom_raster() that squeezed the image when it went outside scale limits (#3539, @thomasp85)

• geom_sf() now determines the legend type automatically (@microly, #3646).

• geom_sf() now removes rows that can't be plotted due to NA aesthetics (#3546, @thomasp85)

• geom_sf() now applies alpha to linestring geometries (#3589, @yutannihilation).

• gg_dep() was deprecated (@perezp44, #3382).

• Added function ggplot_add.by() for lists created with by(), allowing such lists to be added to ggplot objects (#2734, @Maschette)

• ggplot2 no longer depends on reshape2, which means that it no longer (recursively) needs plyr, stringr, or stringi packages.

• Increase the default nbin of guide_colourbar() to place the ticks more precisely (#3508, @yutannihilation).

• manual_scale() now matches values with the order of breaks whenever values is an unnamed vector. Previously, unnamed values would match with the limits of the scale and ignore the order of any breaks provided. Note that this may change the appearance of plots that previously relied on the unordered behaviour (#2429, @idno0001).

• scale_manual_*(limits = ...) now actually limits the scale (#3262, @yutannihilation).

• Fix a bug when show.legend is a named logical vector (#3461, @yutannihilation).

• Added weight aesthetic option to stat_density() and made scaling of weights the default (@annennenne, #2902)

• stat_density2d() can now take an adjust parameter to scale the default bandwidth. (#2860, @haleyjeppson)

• stat_smooth() uses REML by default, if method = "gam" and gam's method is not specified (@ikosmidis, #2630).

• stacking text when calculating the labels and the y axis with stat_summary() now works (@ikosmidis, #2709)

• stat_summary() and related functions now support rlang-style lambda functions (#3568, @dkahle).

• The data mask pronoun, .data, is now stripped from default labels.

• Addition of partial themes to plots has been made more predictable; stepwise addition of individual partial themes is now equivalent to addition of multple theme elements at once (@clauswilke, #3039).

• Facets now don't fail even when some variable in the spec are not available in all layers (@yutannihilation, #2963).

ggplot2 3.2.1

This is a patch release fixing a few regressions introduced in 3.2.0 as well as fixing some unit tests that broke due to upstream changes.

• position_stack() no longer changes the order of the input data. Changes to the internal behaviour of geom_ribbon() made this reordering problematic with ribbons that spanned y = 0 (#3471)
• Using qplot() with a single positional aesthetic will no longer title the non-specified scale as "NULL" (#3473)
• Fixes unit tests for sf graticule labels caused by changes to sf

ggplot2 3.2.0

This is a minor release with an emphasis on internal changes to make ggplot2 faster and more consistent. The few interface changes will only affect the aesthetics of the plot in minor ways, and will only potentially break code of extension developers if they have relied on internals that have been changed. This release also sees the addition of Hiroaki Yutani (@yutannihilation) to the core developer team.

With the release of R 3.6, ggplot2 now requires the R version to be at least 3.2, as the tidyverse is committed to support 5 major versions of R.

Breaking changes

• Two patches (#2996 and #3050) fixed minor rendering problems. In most cases, the visual changes are so subtle that they are difficult to see with the naked eye. However, these changes are detected by the vdiffr package, and therefore any package developers who use vdiffr to test for visual correctness of ggplot2 plots will have to regenerate all reference images.

• In some cases, ggplot2 now produces a warning or an error for code that previously produced plot output. In all these cases, the previous plot output was accidental, and the plotting code uses the ggplot2 API in a way that would lead to undefined behavior. Examples include a missing group aesthetic in geom_boxplot() (#3316), annotations across multiple facets (#3305), and not using aesthetic mappings when drawing ribbons with geom_ribbon() (#3318).

New features

• This release includes a range of internal changes that speeds up plot generation. None of the changes are user facing and will not break any code, but in general ggplot2 should feel much faster. The changes includes, but are not limited to:

  • Caching ascent and descent dimensions of text to avoid recalculating it for every title.

  • Using a faster data.frame constructor as well as faster indexing into data.frames

  • Removing the plyr dependency, replacing plyr functions with faster equivalents.

• geom_polygon() can now draw polygons with holes using the new subgroup aesthetic. This functionality requires R 3.6.0 (@thomasp85, #3128)

• Aesthetic mappings now accept functions that return NULL (@yutannihilation, #2997).

• stat_function() now accepts rlang/purrr style anonymous functions for the fun parameter (@dkahle, #3159).

• geom_rug() gains an "outside" option to allow for moving the rug tassels to outside the plot area (@njtierney, #3085) and a length option to allow for changing the length of the rug lines (@daniel-wells, #3109).

• All geoms now take a key_glyph paramter that allows users to customize how legend keys are drawn (@clauswilke, #3145). In addition, a new key glyph timeseries is provided to draw nice legends for time series (@mitchelloharawild, #3145).

Extensions

• Layers now have a new member function setup_layer() which is called at the very beginning of the plot building process and which has access to the original input data and the plot object being built. This function allows the creation of custom layers that autogenerate aesthetic mappings based on the input data or that filter the input data in some form. For the time being, this feature is not exported, but it has enabled the development of a new layer type, layer_sf() (see next item). Other special-purpose layer types may be added in the future (@clauswilke, #2872).

• A new layer type layer_sf() can auto-detect and auto-map sf geometry columns in the data. It should be used by extension developers who are writing new sf-based geoms or stats (@clauswilke, #3232).

• x0 and y0 are now recognized positional aesthetics so they will get scaled if used in extension geoms and stats (@thomasp85, #3168)

• Continuous scale limits now accept functions which accept the default limits and return adjusted limits. This makes it possible to write a function that e.g. ensures the limits are always a multiple of 100, regardless of the data (@econandrew, #2307).

Minor improvements and bug fixes

• cut_width() now accepts ... to pass further arguments to base::cut.default() like cut_number() and cut_interval() already did (@cderv, #3055)

• coord_map() now can have axes on the top and right (@karawoo, #3042).

• coord_polar() now correctly rescales the secondary axis (@linzi-sg, #3278)

• coord_sf(), coord_map(), and coord_polar() now squash -Inf and Inf into the min and max of the plot (@yutannihilation, #2972).

• coord_sf() graticule lines are now drawn in the same thickness as panel grid lines in coord_cartesian(), and seting panel grid lines to element_blank() now also works in coord_sf() (@clauswilke, #2991, #2525).

• economics data has been regenerated. This leads to some changes in the values of all columns (especially in psavert), but more importantly, strips the grouping attributes from economics_long.

• element_line() now fills closed arrows (@yutannihilation, #2924).

• Facet strips on the left side of plots now have clipping turned on, preventing text from running out of the strip and borders from looking thicker than for other strips (@karawoo, #2772 and #3061).

• ggplot2 now works in Turkish locale (@yutannihilation, #3011).

• Clearer error messages for inappropriate aesthetics (@clairemcwhite, #3060).

• ggplot2 no longer attaches any external packages when using functions that depend on packages that are suggested but not imported by ggplot2. The affected functions include geom_hex(), stat_binhex(), stat_summary_hex(), geom_quantile(), stat_quantile(), and map_data() (@clauswilke, #3126).

• geom_area() and geom_ribbon() now sort the data along the x-axis in the setup_data() method rather than as part of draw_group() (@thomasp85, #3023)

• geom_hline(), geom_vline(), and geom_abline() now throw a warning if the user supplies both an xintercept, yintercept, or slope value and a mapping (@RichardJActon, #2950).

• geom_rug() now works with coord_flip() (@has2k1, #2987).

• geom_violin() no longer throws an error when quantile lines fall outside the violin polygon (@thomasp85, #3254).

• guide_legend() and guide_colorbar() now use appropriate spacing between legend key glyphs and legend text even if the legend title is missing (@clauswilke, #2943).

• Default labels are now generated more consistently; e.g., symbols no longer get backticks, and long expressions are abbreviated with ... (@yutannihilation, #2981).

• All-Inf layers are now ignored for picking the scale (@yutannihilation, #3184).

• Diverging Brewer colour palette now use the correct mid-point colour (@dariyasydykova, #3072).

• scale_color_continuous() now points to scale_colour_continuous() so that it will handle type = "viridis" as the documentation states (@hlendway, #3079).

• scale_shape_identity() now works correctly with guide = "legend" (@malcolmbarrett, #3029)

• scale_continuous will now draw axis line even if the length of breaks is 0 (@thomasp85, #3257)

• stat_bin() will now error when the number of bins exceeds 1e6 to avoid accidentally freezing the user session (@thomasp85).

• sec_axis() now places ticks accurately when using nonlinear transformations (@dpseidel, #2978).

• facet_wrap() and facet_grid() now automatically remove NULL from facet specs, and accept empty specs (@yutannihilation, #3070, #2986).

• stat_bin() now handles data with only one unique value (@yutannihilation #3047).

• sec_axis() now accepts functions as well as formulas (@yutannihilation, #3031).

• New theme elements allowing different ticks lengths for each axis. For instance, this can be used to have inwards ticks on the x-axis (axis.ticks.length.x) and outwards ticks on the y-axis (axis.ticks.length.y) (@pank, #2935).

• The arguments of Stat*$compute_layer() and Position*$compute_layer() are now renamed to always match the ones of Stat$compute_layer() and Position$compute_layer() (@yutannihilation, #3202).

• geom_*() and stat_*() now accepts purrr-style lambda notation (@yutannihilation, #3138).

• geom_tile() and geom_rect() now draw rectangles without notches at the corners. The style of the corner can be controlled by linejoin parameters (@yutannihilation, #3050).

ggplot2 3.1.0

Breaking changes

This is a minor release and breaking changes have been kept to a minimum. End users of ggplot2 are unlikely to encounter any issues. However, there are a few items that developers of ggplot2 extensions should be aware of. For additional details, see also the discussion accompanying issue #2890.

• In non-user-facing internal code (specifically in the aes() function and in the aesthetics argument of scale functions), ggplot2 now always uses the British spelling for aesthetics containing the word "colour". When users specify a "color" aesthetic it is automatically renamed to "colour". This renaming is also applied to non-standard aesthetics that contain the word "color". For example, "point_color" is renamed to "point_colour". This convention makes it easier to support both British and American spelling for novel, non-standard aesthetics, but it may require some adjustment for packages that have previously introduced non-standard color aesthetics using American spelling. A new function standardise_aes_names() is provided in case extension writers need to perform this renaming in their own code (@clauswilke, #2649).

• Functions that generate other functions (closures) now force the arguments that are used from the generated functions, to avoid hard-to-catch errors. This may affect some users of manual scales (such as scale_colour_manual(), scale_fill_manual(), etc.) who depend on incorrect behavior (@krlmlr, #2807).

• Coord objects now have a function backtransform_range() that returns the panel range in data coordinates. This change may affect developers of custom coords, who now should implement this function. It may also affect developers of custom geoms that use the range() function. In some applications, backtransform_range() may be more appropriate (@clauswilke, #2821).

New features

• coord_sf() has much improved customization of axis tick labels. Labels can now be set manually, and there are two new parameters, label_graticule and label_axes, that can be used to specify which graticules to label on which side of the plot (@clauswilke, #2846, #2857, #2881).

• Two new geoms geom_sf_label() and geom_sf_text() can draw labels and text on sf objects. Under the hood, a new stat_sf_coordinates() calculates the x and y coordinates from the coordinates of the sf geometries. You can customize the calculation method via fun.geometry argument (@yutannihilation, #2761).

Minor improvements and fixes

• benchplot() now uses tidy evaluation (@dpseidel, #2699).

• The error message in compute_aesthetics() now only provides the names of aesthetics with mismatched lengths, rather than all aesthetics (@karawoo, #2853).

• For faceted plots, data is no longer internally reordered. This makes it safer to feed data columns into aes() or into parameters of geoms or stats. However, doing so remains discouraged (@clauswilke, #2694).

• coord_sf() now also understands the clip argument, just like the other coords (@clauswilke, #2938).

• fortify() now displays a more informative error message for grouped_df() objects when dplyr is not installed (@jimhester, #2822).

• All geom_*() now display an informative error message when required aesthetics are missing (@dpseidel, #2637 and #2706).

• geom_boxplot() now understands the width parameter even when used with a non-standard stat, such as stat_identity() (@clauswilke, #2893).

• geom_hex() now understands the size and linetype aesthetics (@mikmart, #2488).

• geom_hline(), geom_vline(), and geom_abline() now work properly with coord_trans() (@clauswilke, #2149, #2812).

• geom_text(..., parse = TRUE) now correctly renders the expected number of items instead of silently dropping items that are empty expressions, e.g. the empty string "". If an expression spans multiple lines, we take just the first line and drop the rest. This same issue is also fixed for geom_label() and the axis labels for geom_sf() (@slowkow, #2867).

• geom_sf() now respects lineend, linejoin, and linemitre parameters for lines and polygons (@alistaire47, #2826).

• ggsave() now exits without creating a new graphics device if previously none was open (@clauswilke, #2363).

• labs() now has named arguments title, subtitle, caption, and tag. Also, labs() now accepts tidyeval (@yutannihilation, #2669).

• position_nudge() is now more robust and nudges only in the direction requested. This enables, for example, the horizontal nudging of boxplots (@clauswilke, #2733).

• sec_axis() and dup_axis() now return appropriate breaks for the secondary axis when applied to log transformed scales (@dpseidel, #2729).

• sec_axis() now works as expected when used in combination with tidy eval (@dpseidel, #2788).

• scale_*_date(), scale_*_time() and scale_*_datetime() can now display a secondary axis that is a one-to-one transformation of the primary axis, implemented using the sec.axis argument to the scale constructor (@dpseidel, #2244).

• stat_contour(), stat_density2d(), stat_bin2d(), stat_binhex() now calculate normalized statistics including nlevel, ndensity, and ncount. Also, stat_density() now includes the calculated statistic nlevel, an alias for scaled, to better match the syntax of stat_bin() (@bjreisman, #2679).

ggplot2 3.0.0

Breaking changes

• ggplot2 now supports/uses tidy evaluation (as described below). This is a major change and breaks a number of packages; we made this breaking change because it is important to make ggplot2 more programmable, and to be more consistent with the rest of the tidyverse. The best general (and detailed) introduction to tidy evaluation can be found in the meta programming chapters in Advanced R.

  The primary developer facing change is that aes() now contains quosures (expression + environment pairs) rather than symbols, and you'll need to take a different approach to extracting the information you need. A common symptom of this change are errors "undefined columns selected" or "invalid 'type' (list) of argument" (#2610). As in the previous version, constants (like aes(x = 1) or aes(colour = "smoothed")) are stored as is.

  In this version of ggplot2, if you need to describe a mapping in a string, use quo_name() (to generate single-line strings; longer expressions may be abbreviated) or quo_text() (to generate non-abbreviated strings that may span multiple lines). If you do need to extract the value of a variable instead use rlang::eval_tidy(). You may want to condition on (packageVersion("ggplot2") <= "2.2.1") so that your code can work with both released and development versions of ggplot2.

  We recognise that this is a big change and if you're not already familiar with rlang, there's a lot to learn. If you are stuck, or need any help, please reach out on https://forum.posit.co/.

• Error: Column y must be a 1d atomic vector or a list

  Internally, ggplot2 now uses as.data.frame(tibble::as_tibble(x)) to convert a list into a data frame. This improves ggplot2's support for list-columns (needed for sf support), at a small cost: you can no longer use matrix-columns. Note that unlike tibble we still allow column vectors such as returned by base::scale() because of their widespread use.

• Error: More than one expression parsed

  Previously aes_string(x = c("a", "b", "c")) silently returned aes(x = a). Now this is a clear error.

• Error: data must be uniquely named but has duplicate columns

  If layer data contains columns with identical names an error will be thrown. In earlier versions the first occurring column was chosen silently, potentially masking that the wrong data was chosen.

• Error: Aesthetics must be either length 1 or the same as the data

  Layers are stricter about the columns they will combine into a single data frame. Each aesthetic now must be either the same length as the data frame or a single value. This makes silent recycling errors much less likely.

• Error: coord_* doesn't support free scales

  Free scales only work with selected coordinate systems; previously you'd get an incorrect plot.

• Error in f(...) : unused argument (range = c(0, 1))

  This is because the oob argument to scale has been set to a function that only takes a single argument; it needs to take two arguments (x, and range).

• Error: unused argument (output)

  The function guide_train() now has an optional parameter aesthetic that allows you to override the aesthetic setting in the scale. To make your code work with the both released and development versions of ggplot2 appropriate, add aesthetic = NULL to the guide_train() method signature.

  # old
  guide_train.legend <- function(guide, scale) {...}
  
  # new 
  guide_train.legend <- function(guide, scale, aesthetic = NULL) {...}

  Then, inside the function, replace scale$aesthetics[1], aesthetic %||% scale$aesthetics[1]. (The %||% operator is defined in the rlang package).

  # old
  setNames(list(scale$map(breaks)), scale$aesthetics[1])
  
  # new
  setNames(list(scale$map(breaks)), aesthetic %||% scale$aesthetics[1])

• The long-deprecated subset argument to layer() has been removed.

Tidy evaluation

• aes() now supports quasiquotation so that you can use !!, !!!, and :=. This replaces aes_() and aes_string() which are now soft-deprecated (but will remain around for a long time).

• facet_wrap() and facet_grid() now support vars() inputs. Like dplyr::vars(), this helper quotes its inputs and supports quasiquotation. For instance, you can now supply faceting variables like this: facet_wrap(vars(am, cyl)) instead of facet_wrap(~am + cyl). Note that the formula interface is not going away and will not be deprecated. vars() is simply meant to make it easier to create functions around facet_wrap() and facet_grid().

  The first two arguments of facet_grid() become rows and cols and now support vars() inputs. Note however that we took special care to ensure complete backward compatibility. With this change facet_grid(vars(cyl), vars(am, vs)) is equivalent to facet_grid(cyl ~ am + vs), and facet_grid(cols = vars(am, vs)) is equivalent to facet_grid(. ~ am + vs).

  One nice aspect of the new interface is that you can now easily supply names: facet_grid(vars(Cylinder = cyl), labeller = label_both) will give nice label titles to the facets. Of course, those names can be unquoted with the usual tidy eval syntax.

sf

• ggplot2 now has full support for sf with geom_sf() and coord_sf():

  nc <- sf::st_read(system.file("shape/nc.shp", package = "sf"), quiet = TRUE)
  ggplot(nc) +
    geom_sf(aes(fill = AREA))

  It supports all simple features, automatically aligns CRS across layers, sets up the correct aspect ratio, and draws a graticule.

New features

• ggplot2 now works on R 3.1 onwards, and uses the vdiffr package for visual testing.

• In most cases, accidentally using %>% instead of + will generate an informative error (#2400).

• New syntax for calculated aesthetics. Instead of using aes(y = ..count..) you can (and should!) use aes(y = stat(count)). stat() is a real function with documentation which hopefully will make this part of ggplot2 less confusing (#2059).

  stat() is particularly nice for more complex calculations because you only need to specify it once: aes(y = stat(count / max(count))), rather than aes(y = ..count.. / max(..count..))

• New tag label for adding identification tags to plots, typically used for labelling a subplot with a letter. Add a tag with labs(tag = "A"), style it with the plot.tag theme element, and control position with the plot.tag.position theme setting (@thomasp85).

Layers: geoms, stats, and position adjustments

• geom_segment() and geom_curve() have a new arrow.fill parameter which allows you to specify a separate fill colour for closed arrowheads (@hrbrmstr and @clauswilke, #2375).

• geom_point() and friends can now take shapes as strings instead of integers, e.g. geom_point(shape = "diamond") (@daniel-barnett, #2075).

• position_dodge() gains a preserve argument that allows you to control whether the total width at each x value is preserved (the current default), or ensure that the width of a single element is preserved (what many people want) (#1935).

• New position_dodge2() provides enhanced dodging for boxplots. Compared to position_dodge(), position_dodge2() compares xmin and xmax values
  to determine which elements overlap, and spreads overlapping elements evenly within the region of overlap. position_dodge2() is now the default position adjustment for geom_boxplot(), because it handles varwidth = TRUE, and will be considered for other geoms in the future.

  The padding parameter adds a small amount of padding between elements (@karawoo, #2143) and a reverse parameter allows you to reverse the order of placement (@karawoo, #2171).

• New stat_qq_line() makes it easy to add a simple line to a Q-Q plot, which makes it easier to judge the fit of the theoretical distribution (@nicksolomon).

Scales and guides

• Improved support for mapping date/time variables to alpha, size, colour, and fill aesthetics, including date_breaks and date_labels arguments (@karawoo, #1526), and new scale_alpha() variants (@karawoo, #1526).

• Improved support for ordered factors. Ordered factors throw a warning when mapped to shape (unordered factors do not), and do not throw warnings when mapped to size or alpha (unordered factors do). Viridis is used as the default colour and fill scale for ordered factors (@karawoo, #1526).

• The expand argument of scale_*_continuous() and scale_*_discrete() now accepts separate expansion values for the lower and upper range limits. The expansion limits can be specified using the convenience function expand_scale().

  Separate expansion limits may be useful for bar charts, e.g. if one wants the bottom of the bars to be flush with the x axis but still leave some (automatically calculated amount of) space above them:

  ggplot(mtcars) +
      geom_bar(aes(x = factor(cyl))) +
      scale_y_continuous(expand = expand_scale(mult = c(0, .1)))

  It can also be useful for line charts, e.g. for counts over time, where one wants to have a ’hard’ lower limit of y = 0 but leave the upper limit unspecified (and perhaps differing between panels), with some extra space above the highest point on the line (with symmetrical limits, the extra space above the highest point could in some cases cause the lower limit to be negative).

  The old syntax for the expand argument will, of course, continue to work (@huftis, #1669).

• scale_colour_continuous() and scale_colour_gradient() are now controlled by global options ggplot2.continuous.colour and ggplot2.continuous.fill. These can be set to "gradient" (the default) or "viridis" (@karawoo).

• New scale_colour_viridis_c()/scale_fill_viridis_c() (continuous) and scale_colour_viridis_d()/scale_fill_viridis_d() (discrete) make it easy to use Viridis colour scales (@karawoo, #1526).

• Guides for geom_text() now accept custom labels with guide_legend(override.aes = list(label = "foo")) (@brianwdavis, #2458).

Margins

• Strips gain margins on all sides by default. This means that to fully justify text to the edge of a strip, you will need to also set the margins to 0 (@karawoo).

• Rotated strip labels now correctly understand hjust and vjust parameters at all angles (@karawoo).

• Strip labels now understand justification relative to the direction of the text, meaning that in y facets, the strip text can be placed at either end of the strip using hjust (@karawoo).

• Legend titles and labels get a little extra space around them, which prevents legend titles from overlapping the legend at large font sizes (@karawoo, #1881).

Extension points

• New autolayer() S3 generic (@mitchelloharawild, #1974). This is similar to autoplot() but produces layers rather than complete plots.

• Custom objects can now be added using + if a ggplot_add method has been defined for the class of the object (@thomasp85).

• Theme elements can now be subclassed. Add a merge_element method to control how properties are inherited from the parent element. Add an element_grob method to define how elements are rendered into grobs (@thomasp85, #1981).

• Coords have gained new extension mechanisms.

  If you have an existing coord extension, you will need to revise the specification of the train() method. It is now called setup_panel_params() (better reflecting what it actually does) and now has arguments scale_x, and scale_y (the x and y scales respectively) and param, a list of plot specific parameters generated by setup_params().

  What was formerly called scale_details (in coords), panel_ranges (in layout) and panel_scales (in geoms) are now consistently called panel_params (#1311). These are parameters of the coord that vary from panel to panel.

• ggplot_build() and ggplot_gtable() are now generics, so ggplot-subclasses can define additional behavior during the build stage.

• guide_train(), guide_merge(), guide_geom(), and guide_gengrob() are now exported as they are needed if you want to design your own guide. They are not currently documented; use at your own risk (#2528).

• scale_type() generic is now exported and documented. Use this if you want to extend ggplot2 to work with a new type of vector.

Minor bug fixes and improvements

Faceting

• facet_grid() gives a more informative error message if you try to use a variable in both rows and cols (#1928).

• facet_grid() and facet_wrap() both give better error messages if you attempt to use an unsupported coord with free scales (#2049).

• label_parsed() works once again (#2279).

• You can now style the background of horizontal and vertical strips independently with strip.background.x and strip.background.y theme settings (#2249).

Scales

• discrete_scale() documentation now inherits shared definitions from continuous_scale() (@alistaire47, #2052).

• guide_colorbar() shows all colours of the scale (@has2k1, #2343).

• scale_identity() once again produces legends by default (#2112).

• Tick marks for secondary axes with strong transformations are more accurately placed (@thomasp85, #1992).

• Missing line types now reliably generate missing lines (with standard warning) (#2206).

• Legends now ignore set aesthetics that are not length one (#1932).

• All colour and fill scales now have an aesthetics argument that can be used to set the aesthetic(s) the scale works with. This makes it possible to apply a colour scale to both colour and fill aesthetics at the same time, via aesthetics = c("colour", "fill") (@clauswilke).

• Three new generic scales work with any aesthetic or set of aesthetics: scale_continuous_identity(), scale_discrete_identity(), and scale_discrete_manual() (@clauswilke).

• scale_*_gradient2() now consistently omits points outside limits by rescaling after the limits are enforced (@foo-bar-baz-qux, #2230).

Layers

• geom_label() now correctly produces unbordered labels when label.size is 0, even when saving to PDF (@bfgray3, #2407).

• layer() gives considerably better error messages for incorrectly specified geom, stat, or position (#2401).

• In all layers that use it, linemitre now defaults to 10 (instead of 1) to better match base R.

• geom_boxplot() now supplies a default value if no x aesthetic is present (@foo-bar-baz-qux, #2110).

• geom_density() drops groups with fewer than two data points and throws a warning. For groups with two data points, density values are now calculated with stats::density (@karawoo, #2127).

• geom_segment() now also takes a linejoin parameter. This allows more control over the appearance of the segments, which is especially useful for plotting thick arrows (@Ax3man, #774).

• geom_smooth() now reports the formula used when method = "auto" (@davharris #1951). geom_smooth() now orders by the x aesthetic, making it easier to pass pre-computed values without manual ordering (@izahn, #2028). It also now knows it has ymin and ymax aesthetics (#1939). The legend correctly reflects the status of the se argument when used with stats other than the default (@clauswilke, #1546).

• geom_tile() now once again interprets width and height correctly (@malcolmbarrett, #2510).

• position_jitter() and position_jitterdodge() gain a seed argument that allows the specification of a random seed for reproducible jittering (@krlmlr, #1996 and @slowkow, #2445).

• stat_density() has better behaviour if all groups are dropped because they are too small (#2282).

• stat_summary_bin() now understands the breaks parameter (@karawoo, #2214).

• stat_bin() now accepts functions for binwidth. This allows better binning when faceting along variables with different ranges (@botanize).

• stat_bin() and geom_histogram() now sum correctly when using the weight aesthetic (@jiho, #1921).

• stat_bin() again uses correct scaling for the computed variable ndensity (@timgoodman, #2324).

• stat_bin() and stat_bin_2d() now properly handle the breaks parameter when the scales are transformed (@has2k1, #2366).

• update_geom_defaults() and update_stat_defaults() allow American spelling of aesthetic parameters (@foo-bar-baz-qux, #2299).

• The show.legend parameter now accepts a named logical vector to hide/show only some aesthetics in the legend (@tutuchan, #1798).

• Layers now silently ignore unknown aesthetics with value NULL (#1909).

Coords

• Clipping to the plot panel is now configurable, through a clip argument to coordinate systems, e.g. coord_cartesian(clip = "off") (@clauswilke, #2536).

• Like scales, coordinate systems now give you a message when you're replacing an existing coordinate system (#2264).

• coord_polar() now draws secondary axis ticks and labels (@dylan-stark, #2072), and can draw the radius axis on the right (@thomasp85, #2005).

• coord_trans() now generates a warning when a transformation generates non-finite values (@foo-bar-baz-qux, #2147).

Themes

• Complete themes now always override all elements of the default theme (@has2k1, #2058, #2079).

• Themes now set default grid colour in panel.grid rather than individually in panel.grid.major and panel.grid.minor individually. This makes it slightly easier to customise the theme (#2352).

• Fixed bug when setting strips to element_blank() (@thomasp85).

• Axes positioned on the top and to the right can now customize their ticks and lines separately (@thomasp85, #1899).

• Built-in themes gain parameters base_line_size and base_rect_size which control the default sizes of line and rectangle elements (@karawoo, #2176).

• Default themes use rel() to set line widths (@baptiste).

• Themes were tweaked for visual consistency and more graceful behavior when changing the base font size. All absolute heights or widths were replaced with heights or widths that are proportional to the base font size. One relative font size was eliminated (@clauswilke).

• The height of descenders is now calculated solely on font metrics and doesn't change with the specific letters in the string. This fixes minor alignment issues with plot titles, subtitles, and legend titles (#2288, @clauswilke).

Guides

• guide_colorbar() is more configurable: tick marks and color bar frame can now by styled with arguments ticks.colour, ticks.linewidth, frame.colour, frame.linewidth, and frame.linetype (@clauswilke).

• guide_colorbar() now uses legend.spacing.x and legend.spacing.y correctly, and it can handle multi-line titles. Minor tweaks were made to guide_legend() to make sure the two legend functions behave as similarly as possible (@clauswilke, #2397 and #2398).

• The theme elements legend.title and legend.text now respect the settings of margin, hjust, and vjust (@clauswilke, #2465, #1502).

• Non-angle parameters of label.theme or title.theme can now be set in guide_legend() and guide_colorbar() (@clauswilke, #2544).

Other

• fortify() gains a method for tbls (@karawoo, #2218).

• ggplot gains a method for grouped_dfs that adds a .group variable, which computes a unique value for each group. Use it with aes(group = .group) (#2351).

• ggproto() produces objects with class c("ggproto", "gg"), allowing for a more informative error message when adding layers, scales, or other ggproto objects (@jrnold, #2056).

• ggsave()'s DPI argument now supports 3 string options: "retina" (320 DPI), "print" (300 DPI), and "screen" (72 DPI) (@foo-bar-baz-qux, #2156). ggsave() now uses full argument names to avoid partial match warnings (#2355), and correctly restores the previous graphics device when several graphics devices are open (#2363).

• print.ggplot() now returns the original ggplot object, instead of the output from ggplot_build(). Also, the object returned from ggplot_build() now has the class "ggplot_built" (#2034).

• map_data() now works even when purrr is loaded (tidyverse#66).

• New functions summarise_layout(), summarise_coord(), and summarise_layers() summarise the layout, coordinate systems, and layers of a built ggplot object (#2034, @wch). This provides a tested API that (e.g.) shiny can depend on.

• Updated startup messages reflect new resources (#2410, @mine-cetinkaya-rundel).

ggplot2 2.2.1

• Fix usage of structure(NULL) for R-devel compatibility (#1968).

ggplot2 2.2.0

Major new features

Subtitle and caption

Thanks to @hrbrmstr plots now have subtitles and captions, which can be set with the subtitle and caption arguments to ggtitle() and labs(). You can control their appearance with the theme settings plot.caption and plot.subtitle. The main plot title is now left-aligned to better work better with a subtitle. The caption is right-aligned (@hrbrmstr).

Stacking

position_stack() and position_fill() now sort the stacking order to match grouping order. This allows you to control the order through grouping, and ensures that the default legend matches the plot (#1552, #1593). If you want the opposite order (useful if you have horizontal bars and horizontal legend), you can request reverse stacking by using position = position_stack(reverse = TRUE) (#1837).

position_stack() and position_fill() now accepts negative values which will create stacks extending below the x-axis (#1691).

position_stack() and position_fill() gain a vjust argument which makes it easy to (e.g.) display labels in the middle of stacked bars (#1821).

Layers

geom_col() was added to complement geom_bar() (@hrbrmstr). It uses stat="identity" by default, making the y aesthetic mandatory. It does not support any other stat_() and does not provide fallback support for the binwidth parameter. Examples and references in other functions were updated to demonstrate geom_col() usage.

When creating a layer, ggplot2 will warn if you use an unknown aesthetic or an unknown parameter. Compared to the previous version, this is stricter for aesthetics (previously there was no message), and less strict for parameters (previously this threw an error) (#1585).

Facetting

The facet system, as well as the internal panel class, has been rewritten in ggproto. Facets are now extendable in the same manner as geoms and stats, as described in vignette("extending-ggplot2").

We have also added the following new features.

• facet_grid() and facet_wrap() now allow expressions in their faceting formulas (@DanRuderman, #1596).

• When facet_wrap() results in an uneven number of panels, axes will now be drawn underneath the hanging panels (fixes #1607)

• Strips can now be freely positioned in facet_wrap() using the strip.position argument (deprecates switch).

• The relative order of panel, strip, and axis can now be controlled with the theme setting strip.placement that takes either inside (strip between panel and axis) or outside (strip after axis).

• The theme option panel.margin has been deprecated in favour of panel.spacing to more clearly communicate intent.

Extensions

Unfortunately there was a major oversight in the construction of ggproto which lead to extensions capturing the super object at package build time, instead of at package run time (#1826). This problem has been fixed, but requires re-installation of all extension packages.

Scales

• The position of x and y axes can now be changed using the position argument in scale_x_*and scale_y_* which can take top and bottom, and left and right respectively. The themes of top and right axes can be modified using the .top and .right modifiers to axis.text.* and axis.title.*.

Continuous scales

• scale_x_continuous() and scale_y_continuous() can now display a secondary axis that is a one-to-one transformation of the primary axis (e.g. degrees Celcius to degrees Fahrenheit). The secondary axis will be positioned opposite to the primary axis and can be controlled with the sec.axis argument to the scale constructor.

• Scales worry less about having breaks. If no breaks can be computed, the plot will work instead of throwing an uninformative error (#791). This is particularly helpful when you have facets with free scales, and not all panels contain data.

• Scales now warn when transformation introduces infinite values (#1696).

Date time

• scale_*_datetime() now supports time zones. It will use the timezone attached to the variable by default, but can be overridden with the timezone argument.

• New scale_x_time() and scale_y_time() generate reasonable default breaks and labels for hms vectors (#1752).

Discrete scales

The treatment of missing values by discrete scales has been thoroughly overhauled (#1584). The underlying principle is that we can naturally represent missing values on discrete variables (by treating just like another level), so by default we should.

This principle applies to:

• character vectors
• factors with implicit NA
• factors with explicit NA

And to all scales (both position and non-position.)

Compared to the previous version of ggplot2, there are three main changes:

1. scale_x_discrete() and scale_y_discrete() always show discrete NA, regardless of their source

2. If present, NAs are shown in discrete legends.

3. All discrete scales gain a na.translate argument that allows you to control whether NAs are translated to something that can be visualised, or should be left as missing. Note that if you don't translate (i.e. na.translate = FALSE) the missing values will passed on to the layer, which will warning that it's dropping missing values. To suppress the warnings, you'll also need to add na.rm = TRUE to the layer call.

There were also a number of other smaller changes

• Correctly use scale expansion factors.
• Don't preserve space for dropped levels (#1638).
• Only issue one warning when when asking for too many levels (#1674).
• Unicode labels work better on Windows (#1827).
• Warn when used with only continuous data (#1589)

Themes

• The theme() constructor now has named arguments rather than ellipses. This should make autocomplete substantially more useful. The documentation (including examples) has been considerably improved.

• Built-in themes are more visually homogeneous, and match theme_grey better. (@jiho, #1679)

• When computing the height of titles, ggplot2 now includes the height of the descenders (i.e. the bits of g and y that hang beneath the baseline). This improves the margins around titles, particularly the y axis label (#1712). I have also very slightly increased the inner margins of axis titles, and removed the outer margins.

• Theme element inheritance is now easier to work with as modification now overrides default element_blank elements (#1555, #1557, #1565, #1567)

• Horizontal legends (i.e. legends on the top or bottom) are horizontally aligned by default (#1842). Use legend.box = "vertical" to switch back to the previous behaviour.

• element_line() now takes an arrow argument to specify arrows at the end of lines (#1740)

There were a number of tweaks to the theme elements that control legends:

• legend.justification now controls appearance will plotting the legend outside of the plot area. For example, you can use theme(legend.justification = "top") to make the legend align with the top of the plot.

• panel.margin and legend.margin have been renamed to panel.spacing and legend.spacing respectively, to better communicate intent (they only affect spacing between legends and panels, not the margins around them)

• legend.margin now controls margin around individual legends.

• New legend.box.background, legend.box.spacing, and legend.box.margin control the background, spacing, and margin of the legend box (the region that contains all legends).

Bug fixes and minor improvements

• ggplot2 now imports tibble. This ensures that all built-in datasets print compactly even if you haven't explicitly loaded tibble or dplyr (#1677).

• Class of aesthetic mapping is preserved when adding aes() objects (#1624).

• +.gg now works for lists that include data frames.

• annotation_x() now works in the absense of global data (#1655)

• geom_*(show.legend = FALSE) now works for guide_colorbar.

• geom_boxplot() gains new outlier.alpha (@jonathan-g) and outlier.fill (@schloerke, #1787) parameters to control the alpha/fill of outlier points independently of the alpha of the boxes.

• position_jitter() (and hence geom_jitter()) now correctly computes the jitter width/jitter when supplied by the user (#1775, @has2k1).

• geom_contour() more clearly describes what inputs it needs (#1577).

• geom_curve() respects the lineend parameter (#1852).

• geom_histogram() and stat_bin() understand the breaks parameter once more. (#1665). The floating point adjustment for histogram bins is now actually used - it was previously inadvertently ignored (#1651).

• geom_violin() no longer transforms quantile lines with the alpha aesthetic (@mnbram, #1714). It no longer errors when quantiles are requested but data have zero range (#1687). When trim = FALSE it once again has a nice range that allows the density to reach zero (by extending the range 3 bandwidths to either side of the data) (#1700).

• geom_dotplot() works better when faceting and binning on the y-axis. (#1618, @has2k1).

• geom_hexbin() once again supports ..density.. (@mikebirdgeneau, #1688).

• geom_step() gives useful warning if only one data point in layer (#1645).

• layer() gains new check.aes and check.param arguments. These allow geom/stat authors to optional suppress checks for known aesthetics/parameters. Currently this is used only in geom_blank() which powers expand_limits() (#1795).

• All stat_*() display a better error message when required aesthetics are missing.

• stat_bin() and stat_summary_hex() now accept length 1 binwidth (#1610)

• stat_density() gains new argument n, which is passed to underlying function stats::density ("number of equally spaced points at which the density is to be estimated"). (@hbuschme)

• stat_binhex() now again returns count rather than value (#1747)

• stat_ecdf() respects pad argument (#1646).

• stat_smooth() once again informs you about the method it has chosen. It also correctly calculates the size of the largest group within facets.

• x and y scales are now symmetric regarding the list of aesthetics they accept: xmin_final, xmax_final, xlower, xmiddle and xupper are now valid x aesthetics.

• Scale extensions can now override the make_title and make_sec_title methods to let the scale modify the axis/legend titles.

• The random stream is now reset after calling .onAttach() (#2409).

ggplot2 2.1.0

New features

• When mapping an aesthetic to a constant (e.g. geom_smooth(aes(colour = "loess")))), the default guide title is the name of the aesthetic (i.e. "colour"), not the value (i.e. "loess") (#1431).

• layer() now accepts a function as the data argument. The function will be applied to the data passed to the ggplot() function and must return a data.frame (#1527, @thomasp85). This is a more general version of the deprecated subset argument.

• theme_update() now uses the + operator instead of %+replace%, so that unspecified values will no longer be NULLed out. theme_replace() preserves the old behaviour if desired (@oneillkza, #1519).

• stat_bin() has been overhauled to use the same algorithm as ggvis, which has been considerably improved thanks to the advice of Randy Prium (@rpruim). This includes:

  • Better arguments and a better algorithm for determining the origin. You can now specify either boundary or the center of a bin. origin has been deprecated in favour of these arguments.

  • drop is deprecated in favour of pad, which adds extra 0-count bins at either end (needed for frequency polygons). geom_histogram() defaults to pad = FALSE which considerably improves the default limits for the histogram, especially when the bins are big (#1477).

  • The default algorithm does a (somewhat) better job at picking nice widths and origins across a wider range of input data.

  • bins = n now gives a histogram with n bins, not n + 1 (#1487).

Bug fixes

• All \donttest{} examples run.

• All geom_() and stat_() functions now have consistent argument order: data + mapping, then geom/stat/position, then ..., then specific arguments, then arguments common to all layers (#1305). This may break code if you were previously relying on partial name matching, but in the long-term should make ggplot2 easier to use. In particular, you can now set the n parameter in geom_density2d() without it partially matching na.rm (#1485).

• For geoms with both colour and fill, alpha once again only affects fill (Reverts #1371, #1523). This was causing problems for people.

• facet_wrap()/facet_grid() works with multiple empty panels of data (#1445).

• facet_wrap() correctly swaps nrow and ncol when faceting vertically (#1417).

• ggsave("x.svg") now uses svglite to produce the svg (#1432).

• geom_boxplot() now understands outlier.color (#1455).

• geom_path() knows that "solid" (not just 1) represents a solid line (#1534).

• geom_ribbon() preserves missing values so they correctly generate a gap in the ribbon (#1549).

• geom_tile() once again accepts width and height parameters (#1513). It uses draw_key_polygon() for better a legend, including a coloured outline (#1484).

• layer() now automatically adds a na.rm parameter if none is explicitly supplied.

• position_jitterdodge() now works on all possible dodge aesthetics, e.g. color, linetype etc. instead of only based on fill (@bleutner)

• position = "nudge" now works (although it doesn't do anything useful) (#1428).

• The default scale for columns of class "AsIs" is now "identity" (#1518).

• scale_*_discrete() has better defaults when used with purely continuous data (#1542).

• scale_size() warns when used with categorical data.

• scale_size(), scale_colour(), and scale_fill() gain date and date-time variants (#1526).

• stat_bin_hex() and stat_bin_summary() now use the same underlying algorithm so results are consistent (#1383). stat_bin_hex() now accepts a weight aesthetic. To be consistent with related stats, the output variable from stat_bin_hex() is now value instead of count.

• stat_density() gains a bw parameter which makes it easy to get consistent smoothing between facets (@jiho)

• stat-density-2d() no longer ignores the h parameter, and now accepts bins and binwidth parameters to control the number of contours (#1448, @has2k1).

• stat_ecdf() does a better job of adding padding to -Inf/Inf, and gains an argument pad to suppress the padding if not needed (#1467).

• stat_function() gains an xlim parameter (#1528). It once again works with discrete x values (#1509).

• stat_summary() preserves sorted x order which avoids artefacts when display results with geom_smooth() (#1520).

• All elements should now inherit correctly for all themes except theme_void(). (@Katiedaisey, #1555)

• theme_void() was completely void of text but facets and legends still need labels. They are now visible (@jiho).

• You can once again set legend key and height width to unit arithmetic objects (like 2 * unit(1, "cm")) (#1437).

• Eliminate spurious warning if you have a layer with no data and no aesthetics (#1451).

• Removed a superfluous comma in theme-defaults.r code (@jschoeley)

• Fixed a compatibility issue with ggproto and R versions prior to 3.1.2. (#1444)

• Fixed issue where coord_map() fails when given an explicit parameters argument (@tdmcarthur, #1729)

• Fixed issue where geom_errorbarh() had a required x aesthetic (#1933)

ggplot2 2.0.0

Major changes

• ggplot no longer throws an error if your plot has no layers. Instead it automatically adds geom_blank() (#1246).

• New cut_width() is a convenient replacement for the verbose plyr::round_any(), with the additional benefit of offering finer control.

• New geom_count() is a convenient alias to stat_sum(). Use it when you have overlapping points on a scatterplot. stat_sum() now defaults to using counts instead of proportions.

• New geom_curve() adds curved lines, with a similar specification to geom_segment() (@veraanadi, #1088).

• Date and datetime scales now have date_breaks, date_minor_breaks and date_labels arguments so that you never need to use the long scales::date_breaks() or scales::date_format().

• geom_bar() now has it's own stat, distinct from stat_bin() which was also used by geom_histogram(). geom_bar() now uses stat_count() which counts values at each distinct value of x (i.e. it does not bin the data first). This can be useful when you want to show exactly which values are used in a continuous variable.

• geom_point() gains a stroke aesthetic which controls the border width of shapes 21-25 (#1133, @SeySayux). size and stroke are additive so a point with size = 5 and stroke = 5 will have a diameter of 10mm. (#1142)

• New position_nudge() allows you to slightly offset labels (or other geoms) from their corresponding points (#1109).

• scale_size() now maps values to area, not radius. Use scale_radius() if you want the old behaviour (not recommended, except perhaps for lines).

• New stat_summary_bin() works like stat_summary() but on binned data. It's a generalisation of stat_bin() that can compute any aggregate, not just counts (#1274). Both default to mean_se() if no aggregation functions are supplied (#1386).

• Layers are now much stricter about their arguments - you will get an error if you've supplied an argument that isn't an aesthetic or a parameter. This is likely to cause some short-term pain but in the long-term it will make it much easier to spot spelling mistakes and other errors (#1293).

  This change does break a handful of geoms/stats that used ... to pass additional arguments on to the underlying computation. Now geom_smooth()/stat_smooth() and geom_quantile()/stat_quantile() use method.args instead (#1245, #1289); and stat_summary() (#1242), stat_summary_hex(), and stat_summary2d() use fun.args.

Extensibility

There is now an official mechanism for defining Stats, Geoms, and Positions in other packages. See vignette("extending-ggplot2") for details.

• All Geoms, Stats and Positions are now exported, so you can inherit from them when making your own objects (#989).

• ggplot2 no longer uses proto or reference classes. Instead, we now use ggproto, a new OO system designed specifically for ggplot2. Unlike proto and RC, ggproto supports clean cross-package inheritance. Creating a new OO system isn't usually the right way to solve a problem, but I'm pretty sure it was necessary here. Read more about it in the vignette.

• aes_() replaces aes_q(). It also supports formulas, so the most concise SE version of aes(carat, price) is now aes_(~carat, ~price). You may want to use this form in packages, as it will avoid spurious R CMD check warnings about undefined global variables.

Text

• geom_text() has been overhauled to make labelling your data a little easier. It:

  • nudge_x and nudge_y arguments let you offset labels from their corresponding points (#1120).

  • check_overlap = TRUE provides a simple way to avoid overplotting of labels: labels that would otherwise overlap are omitted (#1039).

  • hjust and vjust can now be character vectors: "left", "center", "right", "bottom", "middle", "top". New options include "inward" and "outward" which align text towards and away from the center of the plot respectively.

• geom_label() works like geom_text() but draws a rounded rectangle underneath each label (#1039). This is useful when you want to label plots that are dense with data.

Deprecated features

• The little used aes_auto() has been deprecated.

• aes_q() has been replaced with aes_() to be consistent with SE versions of NSE functions in other packages.

• The order aesthetic is officially deprecated. It never really worked, and was poorly documented.

• The stat and position arguments to qplot() have been deprecated. qplot() is designed for quick plots - if you need to specify position or stat, use ggplot() instead.

• The theme setting axis.ticks.margin has been deprecated: now use the margin property of axis.text.

• stat_abline(), stat_hline() and stat_vline() have been removed: these were never suitable for use other than with geom_abline() etc and were not documented.

• show_guide has been renamed to show.legend: this more accurately reflects what it does (controls appearance of layer in legend), and uses the same convention as other ggplot2 arguments (i.e. a . between names). (Yes, I know that's inconsistent with function names with use _, but it's too late to change now.)

A number of geoms have been renamed to be internally consistent:

• stat_binhex() and stat_bin2d() have been renamed to stat_bin_hex() and stat_bin_2d() (#1274). stat_summary2d() has been renamed to stat_summary_2d(), geom_density2d()/stat_density2d() has been renamed to geom_density_2d()/stat_density_2d().

• stat_spoke() is now geom_spoke() since I realised it's a reparameterisation of geom_segment().

• stat_bindot() has been removed because it's so tightly coupled to geom_dotplot(). If you happened to use stat_bindot(), just change to geom_dotplot() (#1194).

All defunct functions have been removed.

Default appearance

• The default theme_grey() background colour has been changed from "grey90" to "grey92": this makes the background a little less visually prominent.

• Labels and titles have been tweaked for readability:

  • Axes labels are darker.

  • Legend and axis titles are given the same visual treatment.

  • The default font size dropped from 12 to 11. You might be surprised that I've made the default text size smaller as it was already hard for many people to read. It turns out there was a bug in RStudio (fixed in 0.99.724), that shrunk the text of all grid based graphics. Once that was resolved the defaults seemed too big to my eyes.

  • More spacing between titles and borders.

  • Default margins scale with the theme font size, so the appearance at larger font sizes should be considerably improved (#1228).

• alpha now affects both fill and colour aesthetics (#1371).

• element_text() gains a margins argument which allows you to add additional padding around text elements. To help see what's going on use debug = TRUE to display the text region and anchors.

• The default font size in geom_text() has been decreased from 5mm (14 pts) to 3.8 mm (11 pts) to match the new default theme sizes.

• A diagonal line is no longer drawn on bar and rectangle legends. Instead, the border has been tweaked to be more visible, and more closely match the size of line drawn on the plot.

• geom_pointrange() and geom_linerange() get vertical (not horizontal) lines in the legend (#1389).

• The default line size for geom_smooth() has been increased from 0.5 to 1 to make it easier to see when overlaid on data.

• geom_bar() and geom_rect() use a slightly paler shade of grey so they aren't so visually heavy.

• geom_boxplot() now colours outliers the same way as the boxes.

• geom_point() now uses shape 19 instead of 16. This looks much better on the default Linux graphics device. (It's very slightly smaller than the old point, but it shouldn't affect any graphics significantly)

• Sizes in ggplot2 are measured in mm. Previously they were converted to pts (for use in grid) by multiplying by 72 / 25.4. However, grid uses printer's points, not Adobe (big pts), so sizes are now correctly multiplied by 72.27 / 25.4. This is unlikely to noticeably affect display, but it's technically correct (https://youtu.be/hou0lU8WMgo).

• The default legend will now allocate multiple rows (if vertical) or columns (if horizontal) in order to make a legend that is more likely to fit on the screen. You can override with the nrow/ncol arguments to guide_legend()

  p <- ggplot(mpg, aes(displ,hwy, colour = model)) + geom_point()
  p
  p + theme(legend.position = "bottom")
  # Previous behaviour
  p + guides(colour = guide_legend(ncol = 1))

New and updated themes

• New theme_void() is completely empty. It's useful for plots with non- standard coordinates or for drawings (@jiho, #976).

• New theme_dark() has a dark background designed to make colours pop out (@jiho, #1018)

• theme_minimal() became slightly more minimal by removing the axis ticks: labels now line up directly beneath grid lines (@tomschloss, #1084)

• New theme setting panel.ontop (logical) make it possible to place background elements (i.e., gridlines) on top of data. Best used with transparent panel.background (@noamross. #551).

Labelling

The facet labelling system was updated with many new features and a more flexible interface (@lionel-). It now works consistently across grid and wrap facets. The most important user visible changes are:

• facet_wrap() gains a labeller option (#25).

• facet_grid() and facet_wrap() gain a switch argument to display the facet titles near the axes. When switched, the labels become axes subtitles. switch can be set to "x", "y" or "both" (the latter only for grids) to control which margin is switched.

The labellers (such as label_value() or label_both()) also get some new features:

• They now offer the multi_line argument to control whether to display composite facets (those specified as ~var1 + var2) on one or multiple lines.

• In label_bquote() you now refer directly to the names of variables. With this change, you can create math expressions that depend on more than one variable. This math expression can be specified either for the rows or the columns and you can also provide different expressions to each margin.

  As a consequence of these changes, referring to x in backquoted expressions is deprecated.

• Similarly to label_bquote(), labeller() now take .rows and .cols arguments. In addition, it also takes .default. labeller() is useful to customise how particular variables are labelled. The three additional arguments specify how to label the variables are not specifically mentioned, respectively for rows, columns or both. This makes it especially easy to set up a project-wide labeller dispatcher that can be reused across all your plots. See the documentation for an example.

• The new labeller label_context() adapts to the number of factors facetted over. With a single factor, it displays only the values, just as before. But with multiple factors in a composite margin (e.g. with ~cyl + am), the labels are passed over to label_both(). This way the variables names are displayed with the values to help identifying them.

On the programming side, the labeller API has been rewritten in order to offer more control when faceting over multiple factors (e.g. with formulae such as ~cyl + am). This also means that if you have written custom labellers, you will need to update them for this version of ggplot.

• Previously, a labeller function would take variable and value arguments and return a character vector. Now, they take a data frame of character vectors and return a list. The input data frame has one column per factor facetted over and each column in the returned list becomes one line in the strip label. See documentation for more details.

• The labels received by a labeller now contain metadata: their margin (in the "type" attribute) and whether they come from a wrap or a grid facet (in the "facet" attribute).

• Note that the new as_labeller() function operator provides an easy way to transform an existing function to a labeller function. The existing function just needs to take and return a character vector.

Documentation

• Improved documentation for aes(), layer() and much much more.

• I've tried to reduce the use of ... so that you can see all the documentation in one place rather than having to integrate multiple pages. In some cases this has involved adding additional arguments to geoms to make it more clear what you can do:

  • geom_smooth() gains explicit method, se and formula arguments.

  • geom_histogram() gains binwidth, bins, origin and right arguments.

  • geom_jitter() gains width and height arguments to make it easier to control the amount of jittering without using the lengthy position_jitter() function (#1116)

• Use of qplot() in examples has been minimised (#1123, @hrbrmstr). This is inline with the 2nd edition of the ggplot2 box, which minimises the use of qplot() in favour of ggplot().

• Tightly linked geoms and stats (e.g. geom_boxplot() and stat_boxplot()) are now documented in the same file so you can see all the arguments in one place. Variations of the same idea (e.g. geom_path(), geom_line(), and geom_step()) are also documented together.

• It's now obvious that you can set the binwidth parameter for stat_bin_hex(), stat_summary_hex(), stat_bin_2d(), and stat_summary_2d().

• The internals of positions have been cleaned up considerably. You're unlikely to notice any external changes, although the documentation should be a little less confusing since positions now don't list parameters they never use.

Data

• All datasets have class tbl_df so if you also use dplyr, you get a better print method.

• economics has been brought up to date to 2015-04-01.

• New economics_long is the economics data in long form.

• New txhousing dataset containing information about the Texas housing market. Useful for examples that need multiple time series, and for demonstrating model+vis methods.

• New luv_colours dataset which contains the locations of all built-in colors() in Luv space.

• movies has been moved into its own package, ggplot2movies, because it was large and not terribly useful. If you've used the movies dataset, you'll now need to explicitly load the package with library(ggplot2movies).

Bug fixes and minor improvements

• All partially matched arguments and $ have been been replaced with full matches (@jimhester, #1134).

• ggplot2 now exports alpha() from the scales package (#1107), and arrow() and unit() from grid (#1225). This means you don't need attach scales/grid or do scales::/grid:: for these commonly used functions.

• aes_string() now only parses character inputs. This fixes bugs when using it with numbers and non default OutDec settings (#1045).

• annotation_custom() automatically adds a unique id to each grob name, making it easier to plot multiple grobs with the same name (e.g. grobs of ggplot2 graphics) in the same plot (#1256).

• borders() now accepts xlim and ylim arguments for specifying the geographical region of interest (@markpayneatwork, #1392).

• coord_cartesian() applies the same expansion factor to limits as for scales. You can suppress with expand = FALSE (#1207).

• coord_trans() now works when breaks are suppressed (#1422).

• cut_number() gives error message if the number of requested bins can be created because there are two few unique values (#1046).

• Character labels in facet_grid() are no longer (incorrectly) coerced into factors. This caused problems with custom label functions (#1070).

• facet_wrap() and facet_grid() now allow you to use non-standard variable names by surrounding them with backticks (#1067).

• facet_wrap() more carefully checks its nrow and ncol arguments to ensure that they're specified correctly (@richierocks, #962)

• facet_wrap() gains a dir argument to control the direction the panels are wrapped in. The default is "h" for horizontal. Use "v" for vertical layout (#1260).

• geom_abline(), geom_hline() and geom_vline() have been rewritten to have simpler behaviour and be more consistent:

  • stat_abline(), stat_hline() and stat_vline() have been removed: these were never suitable for use other than with geom_abline() etc and were not documented.

  • geom_abline(), geom_vline() and geom_hline() are bound to stat_identity() and position_identity()

  • Intercept parameters can no longer be set to a function.

  • They are all documented in one file, since they are so closely related.

• geom_bin2d() will now let you specify one dimension's breaks exactly, without touching the other dimension's default breaks at all (#1126).

• geom_crossbar() sets grouping correctly so you can display multiple crossbars on one plot. It also makes the default fatten argument a little bigger to make the middle line more obvious (#1125).

• geom_histogram() and geom_smooth() now only inform you about the default values once per layer, rather than once per panel (#1220).

• geom_pointrange() gains fatten argument so you can control the size of the point relative to the size of the line.

• geom_segment() annotations were not transforming with scales (@BrianDiggs, #859).

• geom_smooth() is no longer so chatty. If you want to know what the default smoothing method is, look it up in the documentation! (#1247)

• geom_violin() now has the ability to draw quantile lines (@DanRuderman).

• ggplot() now captures the parent frame to use for evaluation, rather than always defaulting to the global environment. This should make ggplot more suitable to use in more situations (e.g. with knitr)

• ggsave() has been simplified a little to make it easier to maintain. It no longer checks that you're printing a ggplot2 object (so now also works with any grid grob) (#970), and always requires a filename. Parameter device now supports character argument to specify which supported device to use ('pdf', 'png', 'jpeg', etc.), for when it cannot be correctly inferred from the file extension (for example when a temporary filename is supplied server side in shiny apps) (@sebkopf, #939). It no longer opens a graphics device if one isn't already open - this is annoying when you're running from a script (#1326).

• guide_colorbar() creates correct legend if only one color (@krlmlr, #943).

• guide_colorbar() no longer fails when the legend is empty - previously this often masked misspecifications elsewhere in the plot (#967).

• New layer_data() function extracts the data used for plotting for a given layer. It's mostly useful for testing.

• User supplied minor_breaks can now be supplied on the same scale as the data, and will be automatically transformed with by scale (#1385).

• You can now suppress the appearance of an axis/legend title (and the space that would allocated for it) with NULL in the scale_ function. To use the default label, use waiver() (#1145).

• Position adjustments no longer warn about potentially varying ranges because the problem rarely occurs in practice and there are currently a lot of false positives since I don't understand exactly what FP criteria I should be testing.

• scale_fill_grey() now uses red for missing values. This matches scale_colour_grey() and makes it obvious where missing values lie. Override with na.value.

• scale_*_gradient2() defaults to using Lab colour space.

• scale_*_gradientn() now allows colours or colors (#1290)

• scale_y_continuous() now also transforms the lower, middle and upper aesthetics used by geom_boxplot(): this only affects geom_boxplot(stat = "identity") (#1020).

• Legends no longer inherit aesthetics if inherit.aes is FALSE (#1267).

• lims() makes it easy to set the limits of any axis (#1138).

• labels = NULL now works with guide_legend() and guide_colorbar(). (#1175, #1183).

• override.aes now works with American aesthetic spelling, e.g. color

• Scales no longer round data points to improve performance of colour palettes. Instead the scales package now uses a much faster colour interpolation algorithm (#1022).

• scale_*_brewer() and scale_*_distiller() add new direction argument of scales::brewer_pal, making it easier to change the order of colours (@jiho, #1139).

• scale_x_date() now clips dates outside the limits in the same way as scale_x_continuous() (#1090).

• stat_bin() gains bins arguments, which denotes the number of bins. Now you can set bins=100 instead of binwidth=0.5. Note that breaks or binwidth will override it (@tmshn, #1158, #102).

• stat_boxplot() warns if a continuous variable is used for the x aesthetic without also supplying a group aesthetic (#992, @krlmlr).

• stat_summary_2d() and stat_bin_2d() now share exactly the same code for determining breaks from bins, binwidth, and origin.

• stat_summary_2d() and stat_bin_2d() now output in tile/raster compatible form instead of rect compatible form.

• Automatically computed breaks do not lead to an error for transformations like "probit" where the inverse can map to infinity (#871, @krlmlr)

• stat_function() now always evaluates the function on the original scale. Previously it computed the function on transformed scales, giving incorrect values (@BrianDiggs, #1011).

• strip_dots works with anonymous functions within calculated aesthetics (e.g. aes(sapply(..density.., function(x) mean(x)))) (#1154, @NikNakk)

• theme() gains validate = FALSE parameter to turn off validation, and hence store arbitrary additional data in the themes. (@tdhock, #1121)

• Improved the calculation of segments needed to draw the curve representing a line when plotted in polar coordinates. In some cases, the last segment of a multi-segment line was not drawn (@BrianDiggs, #952)