ConvertToReflectometryQ Splitting

[Owen Arnold]

Adaptive binning gives poor resolution outputs when visualised after creating a workspace with ConvertToReflectometryQ. Since the size of the data is usually very small, the default should be for eager splitting, and a small split threshold. We should also explose the splitting parameters, should the user want to tweak with them.

[Owen Arnold]

Splitting parameters actually seem to be set quite fine. Must be something else going on here.

[Owen Arnold]

refs #7397. Update reference results.

Changeset: 3ab7f5e45d20e8fbb4e9b25a18a8a90c223e2569

[Owen Arnold]

refs #7397. Move shared methods into base class.

Changeset: 26c17b45b003416d21604adc749152588eac3053

[Owen Arnold]

refs #7397. Expose splitting.

Expose box splitting by making this algorithm a derived class of the BoxControllerSettingsAlgorithm. Also set sensible defaults for these splitting parameters. Fix the way that the workspace is created such that the box signal and error values are recalculated correctly.

Changeset: 16faee37194c58a8404a138b0e908d10163f799a

[Owen Arnold]

refs #7397. Additional tests provided.

Changeset: 003102e009de72b67f2a7242a729c35229df4337

[Owen Arnold]

refs #7397. Missing dllexport.

Changeset: 2a270ec0fee945e8dbba2d3478518df894e27a5f

[Owen Arnold]

Tester:

Before apply the changes (or by looking at a packaged-deployed version of mantid) run the following script and look at all 3 output md workspaces. Look at them either in the sliceviewer, or by running QueryMDWorkspace, and looking at the signal and error values. Signal and error values are all zero!

def runTest():
        workspace_name = "POLREF00004699"
        workspace_nexus_file = workspace_name + ".nxs"
        
        PIX=1.1E-3 #m
        SC=75
        avgDB=29
        Load(Filename=workspace_nexus_file,OutputWorkspace=workspace_name)
        X=mtd[workspace_name]
        X = ConvertUnits(InputWorkspace=X,Target="Wavelength",AlignBins="1")
        # Reference intensity to normalise by
        CropWorkspace(InputWorkspace=X,OutputWorkspace='Io',XMin=0.8,XMax=14.5,StartWorkspaceIndex=2,EndWorkspaceIndex=2)
        # Crop out transmission and noisy data 
        CropWorkspace(InputWorkspace=X,OutputWorkspace='D',XMin=0.8,XMax=14.5,StartWorkspaceIndex=3)
        Io=mtd['Io']
        D=mtd['D']
    
        # Peform the normaisation step
        Divide(LHSWorkspace=D,RHSWorkspace=Io,OutputWorkspace='I',
               AllowDifferentNumberSpectra='1',ClearRHSWorkspace='1')
        I=mtd['I'][0]
        
        # Automatically determine the SC and averageDB 
        FindReflectometryLines(InputWorkspace=I, StartWavelength=10, OutputWorkspace='spectrum_numbers')
        spectrum_table = mtd['spectrum_numbers']
        
        # Move the detector so that the detector channel matching the reflected beam is at 0,0
        MoveInstrumentComponent(Workspace=I,ComponentName="lineardetector",X=0,Y=0,Z=-PIX*( (SC-avgDB)/2.0 +avgDB) )
        
        # Should now have signed theta vs Lambda
        ConvertSpectrumAxis(InputWorkspace=I,OutputWorkspace='SignedTheta_vs_Wavelength',Target='signed_theta')
        
        # Check that signed two theta is being caluclated correctly (not normalised)
        ws1 = mtd['SignedTheta_vs_Wavelength']
        upperHistogram = ws1.getNumberHistograms()-1
        # MD transformations
        ConvertToReflectometryQ(InputWorkspace='SignedTheta_vs_Wavelength',OutputWorkspace='QxQy',OutputDimensions='Q (lab frame)', Extents='-0.0005,0.0005,0,0.12')
        ConvertToReflectometryQ(InputWorkspace='SignedTheta_vs_Wavelength',OutputWorkspace='KiKf',OutputDimensions='K (incident, final)', Extents='0,0.05,0,0.05')
        ConvertToReflectometryQ(InputWorkspace='SignedTheta_vs_Wavelength',OutputWorkspace='PiPf',OutputDimensions='P (lab frame)', Extents='0,0.1,-0.02,0.15')
        
        
       
runTest()

Now apply the changes and apply the same test. In the slice viewer, you should get visible image, and QueryMDWorkspace should return non-zero values in the signal column.

Other than that. Look at the updated unit tests.

[Owen Arnold]

Tester: You must merge BOTH branches called feature/7397_reflectometry_md_splitting into the mantid and systemtest repositories

[Russell Taylor]

Could you quickly remedy the relevant gcc warnings reported here: ​https://builds.sns.gov/job/ornl_clean_rhel6_develop/warnings22 ?

[Owen Arnold]

refs #7397. Fix GCC warnings.

Changeset: b82c450230a73b8761777442db8ec05eb1f9d9af

[Jay Rainey]

Testing

• Testing on Ubuntu 12.4.
• Passed using the provided script above (Using sliceviewer to view output, which it produces).
• Passed using the ConvertToReflectometryQ method.
• No longer produces GCC warnings.
• Passed all build server tests.

Code review

• No bugs.
• Clean and consistent code.

[Stuart Campbell]

This ticket has been transferred to github issue ​8243