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DefineGaugeVolume v1

../_images/DefineGaugeVolume-v1_dlg.png

DefineGaugeVolume dialog.

Summary

Defines a geometrical shape object to be used as the gauge volume in the AbsorptionCorrection algorithm.

See Also

AbsorptionCorrection

Properties

Name

Direction

Type

Default

Description

Workspace

InOut

MatrixWorkspace

Mandatory

The workspace with which to associate the defined gauge volume

ShapeXML

Input

string

Mandatory

The XML that describes the shape of the gauge volume

Description

Intended for use on data from engineering beamlines, this algorithm creates a shape object for use as the ‘gauge volume’ (i.e. the portion of the sample that is visible to the detectors in a given run) of a larger sample in the AbsorptionCorrection v1 algorithm. The sample shape will also need to be defined using, e.g., the CreateSampleShape v1 algorithm. Shapes are defined using XML descriptions that can be found here.

Internally, this works by attaching the XML string (after validating it) to a property called “GaugeVolume” on the workspace’s Run object.

Usage

Example: A simple spherical sample with a cuboid gauge volume

#setup the sample shape
sphere = '''<sphere id="sample-sphere">
      <centre x="0" y="0" z="0"/>
      <radius val=".2" />
  </sphere>'''
ws = CreateSampleWorkspace("Histogram",NumBanks=1,BankPixelWidth=1)
ws = ConvertUnits(ws,"Wavelength")
ws = Rebin(ws,Params=[1])
CreateSampleShape(ws,sphere)
SetSampleMaterial(ws,ChemicalFormula="V")

#setup the gauge volume
cuboid = '''<cuboid id="shape">
    <left-front-bottom-point x="0.01" y="-0.1" z="0.0"  />
    <left-front-top-point  x="0.01" y="-0.1" z="0.02"  />
    <left-back-bottom-point  x="-0.01" y="-0.1" z="0.0"  />
    <right-front-bottom-point  x="0.01" y="0.1" z="0.0"  />
  </cuboid>'''
DefineGaugeVolume(ws,cuboid)

#restrict the number of wavelength points to speed up the example
wsOut = AbsorptionCorrection(ws, NumberOfWavelengthPoints=5, ElementSize=2)

print("The created workspace has one entry for each spectra: {}".format(wsOut.getNumberHistograms()))

Output:

The created workspace has one entry for each spectra: 1

Categories: AlgorithmIndex | Sample

Source

C++ header: DefineGaugeVolume.h

C++ source: DefineGaugeVolume.cpp