groupdata2 1.2.0

• Adds Zenodo DOI for easier citation.

• Adds lifecycle badges to function documentation.

• Adds argument handle_na to differs_from_previous() and find_starts().

• Bug fix: In grouping functions with method l_starts and n = "auto", NAs are now replaced by a unique value before finding group starts. E.g. c(1,1,1,2,2,NA,NA,4,4) yields 4 groups.

• More explicit: the data argument in fold() and participant takes a data frame, not a vector.

• Possibly breaking change: Adds checkmate input checks. Improves error messages but also restricts behavior.

• Adds xpectr as suggested package. Doubles number of unit tests.

Unit test compatibility and all_groups_identical()

• Adds all_groups_identical() for testing if two grouping factors contain the same groups, looking only at the group members, allowing for different group names / identifiers.
• Unit tests were made compatible with R versions lower than 3.6.
• Adds badges to README, including travis-ci status, AppVeyor status, Codecov, min. required R version, CRAN version and monthly CRAN downloads. Note: Zenodo badge will be added post release.

Minor Patch

• Bug fix: fold() ungroups dataset before removing existing fold columns.
• Unit tests are skipped on R versions lower than 3.6. This is done as they fail due to v3.5 having a different random sampling generator than v3.6.
• Improved documentation

New features and improvements

• New main function: balance() used for up- and downsampling of data to balance sample size within categories and IDs.
  Thanks for the request from @jjesusfilho (#3).

• New wrapper function: upsample() wraps balance() with size="max".

• New wrapper function: downsample() wraps balance() with size="min".

• Adds parameter "num_col" to fold() and partition() for balancing on a numerical column.

• Adds parameter "id_aggregation_fn" to fold() and partition(). Used when balancing on both id_col and num_col.

• Adds helper tool 'differs_from_previous'. Finds values in a vector that differs from the previous value by some threshold. Similar to find_starts().

• Adds parameter "num_fold_cols" to fold(). Useful for creating multiple fold columns for repeated cross-validation.

• Adds parameter "unique_fold_cols_only" to fold(). Whether to only include unique fold columns or not.

• Adds parameter "max_iters" to fold(). How many times to attempt creating unique fold columns. Note that it is possible to get fewer fold columns than specified in "num_fold_cols".

• Adds parameter "parallel" to fold(). When creating multiple unique fold columns, we can run the column comparisons in parallel. Requires registered parallel backend.

• Adds parameter "handle_existing_fold_cols" to fold(). When calling fold() on a data frame that already contains columns with names starting with ".folds", we can either keep them and add more, or replace them.

• Fixed behavior in fold() when k is a percentage (between 0-1). It is now interpreted as the approximate size of each fold and used to calculate the number of folds. E.g. k=0.2 will lead to 5 folds.

Major release

Introduces a lot of new functionality and better vignettes.

News:

• New main function: partition() - used for creating balanced partitions by partition sizes

• New method category: l_ methods - n is passed as a list

• New method: 'l_sizes' - Uses list of group sizes to create grouping factor. Can be used for partitioning (e.g. n = c(0.2, 0.3) returns 3 groups with 0.2 (20%), 0.3 (30%) and the exceeding 0.5 (50%) of the data points)

• New method: 'l_starts' - Uses list of start positions to create groups. Define which values from a vector to start a new group at. Skip to later appearances of a value. Use n = 'auto' to automatically find starts using find_starts()

• New helper tool: 'find_starts' - Finds start positions in a vector. I.e. values that differ from the previous value. Get the values or indices of the values. Output can be used as n in 'l_starts' method.

• New helper tool: 'find_missing_starts' - Returns the start posititions that would be recursively removed when using the 'l_starts' with remove_missing_starts set to TRUE.

• Added argument 'remove_missing_starts' to grouping functions. Recursively remove the starting positions not found with 'l_starts' method.

• New method: 'primes' - similar to 'staircase' but with primes as steps (e.g. group sizes 2,3,5,7..)

• New remainder tool: '%primes%' - similar to %staircase% but for the new primes method

First release

This is the first release of groupdata2. It has been accepted at CRAN.
Main functions and tools of this version is group_factor(), group(), splt(), fold(), and %staircase%.

Enjoy,

• Ludvig