PeaksOverlays HKL when using ConvertToMD

[Owen Arnold]

The workspace outputs are different between ConvertToMD (newer) and the older ConvertToDiffractionMDWorkspace algorithm. In particular the Dimension labels are different, and this means that the PeaksOverlay does not recognise the output workspace as one that can be overplotted.

Follow the usual SC Workflow

• Create a MDWorkspace using ConvertToMD in QLab
• FindPeaksMD on the Workspace
• Find the UB from the PeaksWorkspace and Index the PeaksWorkspace
• Copy the UB over to the input EventWorkspace
• Repeat ConvertToMD, but this time convert to HKL
• Plot the output HKL workspace in the SliceViewer, notice that the Peaks Overlay button (star) is disabled.

The procedure above works if you use ConvertToDiffractionMDWorkspace (version 1) rather than ConvertToMD.

This is probably an issue with an inflexible Regex, however, it should also be possible to getSpecialCoordinates and determine the coordinate system that way round.

[Owen Arnold]

One thing we can and should do here now, as part of these changes is to update the python tests such that they ensure that workspaces generated via ConvertToMD can open (along with respective peaks workspaces in the SliceViewer). This is probably best done under a separate ticket.

These changes should be possible owing to this #7013.

[Owen Arnold]

refs #7824. Make regex more flexible.

Effectively introduce an OR into the regex. This allows it to process the newer form of the HKL coordinate transform labels. Should also still work with the old ones.

Changeset: b9f3cd99ee97baeb85966022add3ad3caee3faa6

[Owen Arnold]

refs #7824. Correct Regex.

Changeset: 7f2fb4fe73d6264d66bb5c17a8a4ba01539488e7

[Owen Arnold]

Tester (It would probably be better if the tester for this was familiar with the existing behaviour of the PeaksViewer):

• Run ConvertToMDUnitTests.py on an old copy of MantidPlot. You should find that you cannot use the PeaksViewer http://www.mantidproject.org/PeaksViewer on the generated HKL workspace.
• Now build with these changes. Should find that PeaksViewer is enabled, and should overplot the peaks workspace correctly.

I also have unit tests for these changes.

[Andrei Savici]

Merge remote-tracking branch 'origin/feature/7827_fix_hkl_transform'

[Stuart Campbell]

This ticket has been transferred to github issue ​8672