FullCBFWriter: Fix bug causing panel shuffling (cctbx#752)

newsfragments/752.bugfix

@@ -0,0 +1 @@
+Stop ``dxtbx.image_average`` shuffling panel positions for segmented detectors.

src/dxtbx/format/cbf_writer.py

@@ -215,6 +215,7 @@ def level_string(key):
  detector_axes_names = [] # save these for later
  panelkeys = []
  panelnames = []
+ panelindices = []
 
  def recursive_setup_basis_dict(key, parent_name="", panel_id=0):
  # Set up CBF axis names, including equipment components and depends_on chains
@@ -230,6 +231,8 @@ def recursive_setup_basis_dict(key, parent_name="", panel_id=0):
  panelname = "PANEL_%d" % panel_id
  panelkeys.append(key)
  panelnames.append(panelname)
+ dxtbx_panel_index = list(detector).index(node)
+ panelindices.append(dxtbx_panel_index)
  panel_id += 1
 
  if len(key) == 1:
@@ -253,6 +256,11 @@ def recursive_setup_basis_dict(key, parent_name="", panel_id=0):
  return panel_id
 
  recursive_setup_basis_dict((0,))
+ # The order `recursive_setup_basis_dict` visits panels does not necessarily match
+ # the order returned by dxtbx's `get_detector` and `get_raw_data`.
+ # See https://github.com/cctbx/dxtbx/issues/745.
+ self.panelindices = panelindices # needed in add_data_to_cbf
+ sorted_panels = [detector[i] for i in panelindices]
 
  if index is None:
  cbf_root = self.imageset.paths()[0]
@@ -327,7 +335,7 @@ def recursive_setup_basis_dict(key, parent_name="", panel_id=0):
  # defined as [min-trusted-value, max-trusted-value]. The CBF definition
  # of 'overload' is in fact saturation - i.e. the max-trusted-value, while
  # the undefined_value is below the min-trusted-value.
- trusted_ranges = [panel.get_trusted_range() for panel in detector]
+ trusted_ranges = [panel.get_trusted_range() for panel in sorted_panels]
  try:
  add_frame_specific_cbf_tables(
  cbf,
@@ -336,7 +344,7 @@ def recursive_setup_basis_dict(key, parent_name="", panel_id=0):
  trusted_ranges,
  diffrn_id,
  False,
- gain=[panel.get_gain() for panel in detector],
+ gain=[panel.get_gain() for panel in sorted_panels],
  flux=beam.get_flux(),
  )
  except TypeError:
@@ -348,7 +356,7 @@ def recursive_setup_basis_dict(key, parent_name="", panel_id=0):
  trusted_ranges,
  diffrn_id,
  False,
- gain=[panel.get_gain() for panel in detector],
+ gain=[panel.get_gain() for panel in sorted_panels],
  )
 
  """Data items in the AXIS category record the information required
@@ -596,6 +604,7 @@ def add_data_to_cbf(self, cbf, index=None, data=None, verbose=False):
  data = self.imageset.get_raw_data(index)
  if not isinstance(data, tuple):
  data = (data,)
+ data = tuple([data[i] for i in self.panelindices])
 
  array_names = []
  cbf.find_category(b"diffrn_data_frame")