Expose more of ReferenceFrame to Python

[Owen Arnold]

Looks like one of the areas of inflexibility that the reflectometry group at ISIS suffer is that the instrument definitions are set up with different reference frames. For example, INTER has z as the beam direction, and y as the up direction, while POLREF has x as the bam direction and z as the up direction. This means that scripts like this ​https://github.com/mantidproject/mantid/blob/master/Code/Mantid/scripts/Reflectometry/isis_reflgui/l2q.py (created by our users) have to be written on an instrument by instrument basis to be correct. Because the offset calculation requires knowledge of the instrument reference frame to be correct.

I'd like to point them to a feature I have already exposed in python that will solve this issue for them, and that's the ReferenceFrame. However, It would be better to expose more useful features of this utility before drawing their attention to it.

[Owen Arnold]

Tester: Once done, the following should give sensible answers in both the old and new API. You should compare the results given to the reference frame entry in the IDF, and check that this works in both the old and new API.

ws = Load(Filename="POLREF00004699.nxs")
ws = ws[0]
inst=ws.getInstrument()
ref = inst.getReferenceFrame()

print ref.pointingAlongBeam()
print ref.vecPointingAlongBeam()

print ref.pointingUp()
print ref.vecPointingUp()

Here it is in the old API

from mantidsimple import *
Load(Filename="POLREF00004699.nxs", OutputWorkspace='ws')
ws = mtd['ws']
ws = ws[0]
inst=ws.getInstrument()
ref = inst.getReferenceFrame()

print ref.pointingAlongBeam()
print ref.vecPointingAlongBeam()

print ref.pointingUp()
print ref.vecPointingUp()

[Owen Arnold]

refs #7323. Expose reference frame aspects to python.

Changeset: 003fc784e165defe16b0b1d7a8e5bd0f139828d6

[Owen Arnold]

Branch is feature/7323_reference_frame. Follow test instructions above.

[Owen Arnold]

refs #7323. Expose reference frame aspects to python.

Changeset: 449675361960a781f05294c1380d5a83bd3f37fe

[Martyn Gigg]

Code is fine & tests do what they are expected to do.

[Stuart Campbell]

This ticket has been transferred to github issue ​8169