Mask2Cal: algorithm to convert mask workspaces into cal files

[Nick Draper]

A python algorithm that will convert mask workspaces into cal files.

This converts the masked detectors into a focussing group. select and offsets values will be entered as defaults.

[Roman Tolchenov]

In [14814]:

Added MaskWorkspaceToCalFile python algorithm which fixes #3782

[Janik Zikovsky]

Why not use the the SaveCalFile algorithm?

[Russell Taylor]

SaveCalFile doesn't do quite the same thing as this algorithm, in that it toggles the 'select' column rather than the 'group' column based on the mask value (group always being 1 in this case). It also bases its output on the instrument rather than the workspace (e.g. monitors end up in the file even if they're not in the input workspace).

Having said that, DiffractionFocussing fails on the output of MaskWorkspaceToCalFile - which I tried by generating the file off a MaskWorkspace created by the InstrumentWindow, and also by first running LoadCalFile to create the mask workspace (note that this is different to the instrument view one - it is of type 'SpecialWorkspace2D' and includes all pixels whereas the instrument view one appears to only include the first pixel in a group - it steps by 4 for WISH - which is probably not be the right thing to do).

DiffrationFocussing works on a cal file generated by LoadCalFile followed by SaveCalFile.

[Roman Tolchenov]

In [14823]:

DetectorGroups are taken into account. re #3782

[Russell Taylor]

The produced file now expands out detector groups correctly. DiffractionFocussing works in the scenarios described above. Since the mask workspace from the instrument view holds the detector grouping internally, I would think there's no problem there after all.

[Stuart Campbell]

This ticket has been transferred to github issue ​4629