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CalculateCoverageDGS v1

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Summary

Calculate the reciprocal space coverage for direct geometry spectrometers

See Also

SetGoniometer, SetUB

Properties

Name	Direction	Type	Default	Description
InputWorkspace	Input	MatrixWorkspace	Mandatory	An input workspace.
Q1Basis	Input	dbl list	1,0,0	Q1 projection direction in the x,y,z format. Q1, Q2, Q3 must not be coplanar
Q2Basis	Input	dbl list	0,1,0	Q2 projection direction in the x,y,z format. Q1, Q2, Q3 must not be coplanar
Q3Basis	Input	dbl list	0,0,1	Q3 projection direction in the x,y,z format. Q1, Q2, Q3 must not be coplanar
IncidentEnergy	Input	number	Optional	Incident energy. If set, will override Ei in the input workspace
Dimension1	Input	string	Q1	Dimension to bin or integrate. Allowed values: [‘Q1’, ‘Q2’, ‘Q3’, ‘DeltaE’]
Dimension1Min	Input	number	Optional	Dimension1 minimum value. If empty will take minimum possible value.
Dimension1Max	Input	number	Optional	Dimension1 maximum value. If empty will take maximum possible value.
Dimension1Step	Input	number	Optional	Dimension1 step size. If empty the dimension will be integrated between minimum and maximum values
Dimension2	Input	string	Q2	Dimension to bin or integrate. Allowed values: [‘Q1’, ‘Q2’, ‘Q3’, ‘DeltaE’]
Dimension2Min	Input	number	Optional	Dimension2 minimum value. If empty will take minimum possible value.
Dimension2Max	Input	number	Optional	Dimension2 maximum value. If empty will take maximum possible value.
Dimension2Step	Input	number	Optional	Dimension2 step size. If empty the dimension will be integrated between minimum and maximum values
Dimension3	Input	string	Q3	Dimension to bin or integrate. Allowed values: [‘Q1’, ‘Q2’, ‘Q3’, ‘DeltaE’]
Dimension3Min	Input	number	Optional	Dimension3 minimum value. If empty will take minimum possible value.
Dimension3Max	Input	number	Optional	Dimension3 maximum value. If empty will take maximum possible value.
Dimension3Step	Input	number	Optional	Dimension3 step size. If empty the dimension will be integrated between minimum and maximum values
Dimension4	Input	string	DeltaE	Dimension to bin or integrate. Allowed values: [‘Q1’, ‘Q2’, ‘Q3’, ‘DeltaE’]
Dimension4Min	Input	number	Optional	Dimension4 minimum value. If empty will take minimum possible value.
Dimension4Max	Input	number	Optional	Dimension4 maximum value. If empty will take maximum possible value.
Dimension4Step	Input	number	Optional	Dimension4 step size. If empty the dimension will be integrated between minimum and maximum values
OutputWorkspace	Output	Workspace	Mandatory	A name for the output data MDHistoWorkspace.

Description

The algorithm calculates what part of the reciprocal space is covered by direct geometry spectrometers. It is supposed to be used in planning tools. The input workspace should contain the incident energy log, a goniometer, and the UB matrix. The incident energy can be overwritten by setting the IncidentEnergy parameter. The output is an MDHisto workspace. You can visualize it with Sliceviewer.

The parameters Q1Basis, Q2Basis, Q3Basis can be used to look at different directions in the reciprocal space, such as [H,H,0]

DimensionI, where I is from 1 to 4, allows one to select in which order Q1, Q2, Q3, DeltaE are stored in the output workspace. The algorithm will complain if you select the same dimension twice. For each dimension one can define minimum, maximum, and step size. If no minimum/maximum are set for DeltaE, these are chosen to be +/-Ei. If not specified, minimum/maximum for the Q dimensions are calculated based on the instrument geometry, incident energy, minimum/maximum for DeltaE, and lattice parameters.

The algorithm calculates detector trajectories in the reciprocal space and sets to 1 the corresponding points in the output workspace. All other points are 0.

Usage

Note

To run these usage examples please first download the usage data, and add these to your path. In Mantid this is done using Manage User Directories.

Example - CalculateCoverageDGS

w=Load(Filename="CNCS_7860")
w=ConvertUnits(InputWorkspace=w,Target='DeltaE', EMode='Direct', EFixed='3')
SetGoniometer(Workspace=w, Axis0='30,0,1,0,1')
SetUB(Workspace=w, a='2', b='2', c='2')
w=Rebin(InputWorkspace=w, Params='-3,0.1,3', PreserveEvents='0')
coverage=CalculateCoverageDGS(InputWorkspace=w, IncidentEnergy=3,
    Dimension1Min=-1, Dimension1Max=1, Dimension1Step=0.02,
    Dimension2Min=-1, Dimension2Max=1, Dimension2Step=2,
    Dimension3Min=-1, Dimension3Max=1, Dimension3Step=2,
    Dimension4Min=0, Dimension4Max=3, Dimension4Step=0.1)

# Print the result
print("You cover {:.0f} MD bins out of {}".format(coverage.getSignalArray().sum(),coverage.getSignalArray().size))

Output:

You cover 506 MD bins out of 3000

Categories: AlgorithmIndex | Inelastic\Planning | MDAlgorithms\Planning

Source

C++ header: CalculateCoverageDGS.h

C++ source: CalculateCoverageDGS.cpp