Vesuvio workflow needs to support DetectorGroups

[Martyn Gigg]

This is required so all of the spectra can be summed on loading and the the fitting applied to the summed workspace and averaged detector geometry.

When complete the following script should run successfully:

raw_ws = LoadVesuvio(Filename='14188-14195',OutputWorkspace='raw_ws',SpectrumList='135-142',Mode='SingleDifference',
                InstrumentParFile=r'IP0004_10.par')
raw_ws = SumSpectra(raw_ws)
CropWorkspace(InputWorkspace='raw_ws',OutputWorkspace='raw_ws',XMin=50,XMax=562)

# Convert to seconds
ScaleX(InputWorkspace='raw_ws',OutputWorkspace='raw_ws',Operation='Multiply',Factor=1e-06)
function_str = \
        "composite=ComptonScatteringCountRate,NumDeriv=1,IntensityConstraints=\"Matrix(1|3)0|-1|3\";"\
        "name=GramCharlierComptonProfile,WorkspaceIndex=0,Mass=1.007940,HermiteCoeffs=1 0 1;"\
        "name=GaussianComptonProfile,WorkspaceIndex=0,Mass=27.000000;"\
        "name=GaussianComptonProfile,WorkspaceIndex=0,Mass=91.000000"

ties_str = "f1.Width=10.000000,f2.Width=25.000000"
constraints_str = "2.000000 < f0.Width < 7.000000"

Fit(InputWorkspace='raw_ws',Function=function_str,Ties=ties_str,Constraints=constraints_str,
        Output='fit', CreateOutput=True,OutputCompositeMembers=True,MaxIterations=5000,
        Minimizer="Levenberg-Marquardt,AbsError=1e-08,RelError=1e-08")
# Convert to microseconds
ScaleX(InputWorkspace='fit_Workspace',OutputWorkspace='fit_Workspace',Operation='Multiply',Factor=1e06)
ScaleX(InputWorkspace='raw_ws',OutputWorkspace='raw_ws',Operation='Multiply',Factor=1e06)

# Usually constructed from Fit output parameters in user scripts
mass1_str = "name=GramCharlierComptonProfile,WorkspaceIndex=0,Mass=1.007900,HermiteCoeffs=1 0 0,Width=4.226288,FSECoeff=0.498073,C_0=57.941101"
mass2_str = "name=GaussianComptonProfile,WorkspaceIndex=0,Mass=27.000000,Width=13.000000,Intensity=1.626268"
mass3_str = "name=GaussianComptonProfile,WorkspaceIndex=0,Mass=91.200000,Width=26.000000,Intensity=2.977515"
function_str = "%s;%s;%s" %(mass1_str,mass2_str,mass3_str)

background,corrected = CalculateGammaBackground(InputWorkspace='raw_ws', ComptonFunction=function_str,WorkspaceIndexList=0)

The script currently complains about not being able to find a t0 parameter during Fit.

[Martyn Gigg]

Add support for DetectorGroups to Compton functions

The parameters are averaged across the DetectorGroup when one is found Refs #8593

Changeset: 1745c657d83ec637c970a11eb7b3df107e4455d8

[Martyn Gigg]

Add SumSpectra option to LoadVesuvio

The final output is just a single spectrum when this option is used. Refs #8593

Changeset: e8d6a77377b3612769885660793cb8b7fb44abc8

[Martyn Gigg]

Add a test for LoadVesuvio SumSpectra option.

Refs #8593

Changeset: ff68b3dfcdd1077d8a248b03ac4623fa66cca1e2

[Martyn Gigg]

Branch: feature/8593_compton_scattering_detector_groups in both code & systemtests repositories

Tester: The data is on the ISIS archive & the IP file is attached to #8378.

Run the script above and it should run to completion without error. You can plot the raw_ws,background,corrected workspaces to see that the background has been taken off the raw_ws.

Now run this slightly altered script, sum is on algorithm, and it should give the same values:

raw_ws = LoadVesuvio(Filename='14188-14195',OutputWorkspace='raw_ws',SpectrumList='135-142',Mode='SingleDifference',
                InstrumentParFile=r'IP0004_10.par',SumSpectra=True)
CropWorkspace(InputWorkspace='raw_ws',OutputWorkspace='raw_ws',XMin=50,XMax=562)

# Convert to seconds
ScaleX(InputWorkspace='raw_ws',OutputWorkspace='raw_ws',Operation='Multiply',Factor=1e-06)
function_str = \
        "composite=ComptonScatteringCountRate,NumDeriv=1,IntensityConstraints=\"Matrix(1|3)0|-1|3\";"\
        "name=GramCharlierComptonProfile,WorkspaceIndex=0,Mass=1.007940,HermiteCoeffs=1 0 1;"\
        "name=GaussianComptonProfile,WorkspaceIndex=0,Mass=27.000000;"\
        "name=GaussianComptonProfile,WorkspaceIndex=0,Mass=91.000000"

ties_str = "f1.Width=10.000000,f2.Width=25.000000"
constraints_str = "2.000000 < f0.Width < 7.000000"

Fit(InputWorkspace='raw_ws',Function=function_str,Ties=ties_str,Constraints=constraints_str,
        Output='fit', CreateOutput=True,OutputCompositeMembers=True,MaxIterations=5000,
        Minimizer="Levenberg-Marquardt,AbsError=1e-08,RelError=1e-08")
# Convert to microseconds
ScaleX(InputWorkspace='fit_Workspace',OutputWorkspace='fit_Workspace',Operation='Multiply',Factor=1e06)
ScaleX(InputWorkspace='raw_ws',OutputWorkspace='raw_ws',Operation='Multiply',Factor=1e06)

# Usually constructed from Fit output parameters in user scripts
mass1_str = "name=GramCharlierComptonProfile,WorkspaceIndex=0,Mass=1.007900,HermiteCoeffs=1 0 0,Width=4.226288,FSECoeff=0.498073,C_0=57.941101"
mass2_str = "name=GaussianComptonProfile,WorkspaceIndex=0,Mass=27.000000,Width=13.000000,Intensity=1.626268"
mass3_str = "name=GaussianComptonProfile,WorkspaceIndex=0,Mass=91.200000,Width=26.000000,Intensity=2.977515"
function_str = "%s;%s;%s" %(mass1_str,mass2_str,mass3_str)

background,corrected = CalculateGammaBackground(InputWorkspace='raw_ws', ComptonFunction=function_str,WorkspaceIndexList=0)

[Arturs Bekasovs]

Both scripts provided do work now. Corrected ws does seem to be raw_ws with subtracted background. Updated system test is passing on my machine.

[Arturs Bekasovs]

Merge remote-tracking branch 'origin/feature/8593_compton_scattering_detector_groups'

Full changeset: ​14eff3e66ef3e175059e797767d0e8b279fc6708

[Arturs Bekasovs]

Merge remote-tracking branch 'origin/feature/8593_compton_scattering_detector_groups'

Full changeset: ​19b3681d8043a21f8821489da8cd8be09ae7da68

[Stuart Campbell]

This ticket has been transferred to github issue ​9437