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CreateMDHistoWorkspace v1

CreateMDHistoWorkspace dialog.

Summary

Creates an MDHistoWorkspace from supplied lists of signal and error values.

See Also

ConvertToMD, CreateMDWorkspace

Properties

Name	Direction	Type	Default	Description
SignalInput	Input	dbl list	Mandatory	Signal array for n-dimensional workspace
ErrorInput	Input	dbl list	Mandatory	Error array for n-dimensional workspace
NumberOfEvents	Input	dbl list		Number of pixels array for n-dimensional workspace. Optional, defaults to 1 per bin.
Dimensionality	Input	number	Mandatory	Dimensionality of the data in the file.
Extents	Input	dbl list	Mandatory	A comma separated list of min, max for each dimension, specifying the extents of each dimension.
NumberOfBins	Input	int list	Mandatory	Number of bin in each dimension.
Names	Input	str list	Mandatory	A comma separated list of the name of each dimension. e.g. (‘[H,0,0]’,’[0,K,0]’,’[0,0,L]’)
Units	Input	str list	Mandatory	A comma separated list of the units of each dimension.
OutputWorkspace	Output	IMDHistoWorkspace	Mandatory	MDHistoWorkspace reflecting the input text file.
Frames	Input	str list		A comma separated list of the frames of each dimension. The frames can be General Frame: Any frame which is not a Q-based frame. QLab: Wave-vector converted into the lab frame. QSample: Wave-vector converted into the frame of the sample. HKL: Wave-vector converted into the crystal’s HKL indices. Note if nothing is specified then the General Frame is being selected. Also note that if you select a frame then this might override your unit selection if it is not compatible with the frame.

Description

Takes two arrays of signal and error values, as well as information describing the dimensionality and extents, and creates a MDHistoWorkspace (histogrammed multi-dimensional workspace). The SignalInput and ErrorInput arrays must be of equal length and have a length that is equal to the product of all the comma separated arguments provided to NumberOfBins. The order in which the arguments are specified to each of the properties (for those taking multiple arguments) is important, as they are assumed to match by the order they are declared. For example, specifying Names = A,B and Units = U1,U2 will generate two dimensions, the first with a name of A and units of U1 and the second with a name of B and units of U2. The same logic applies to the Extents inputs. Signal and Error inputs are read in such that, the first entries in the file will be entered across the first dimension specified, and the zeroth index in the other dimensions. The second set of entries will be entered across the first dimension and the 1st index in the second dimension, and the zeroth index in the others.

Alternatives

A very similar algorithm to this is ImportMDHistoWorkspace v1, which takes it’s input signal and error values from a text file rather than from arrays. Another alternative is to use ConvertToMD v1 which works on MatrixWorkspaces, and allows log values to be included in the dimensionality.

Usage

Example - Create MDHistoWorkspace

S  =range(0,100);
ERR=range(0,100);
# create Histo workspace
ws=CreateMDHistoWorkspace(Dimensionality=2,Extents='-3,3,-10,10',SignalInput=S,ErrorInput=ERR,\
                           NumberOfBins='10,10',Names='Dim1,Dim2',Units='MomentumTransfer,EnergyTransfer')

# check it looks like the one we wanted
print('created workspace is of type: {0}'.format(ws.id()))
print('and has {0} dimensions with {1} points and {2} events'.
      format(ws.getNumDims(),ws.getNPoints(),ws.getNEvents()))
d1=ws.getDimension(0)
print('dimension 0 has ID: {0}; nBins={1}; min: {2}; max: {3} in units of: {4}'.
      format(d1.getDimensionId(), d1.getNBins(), d1.getMinimum(), d1.getMaximum(),d1.getUnits()))
d1=ws.getDimension(1)
print('dimension 1 has ID: {0}; nBins={1}; min: {2}; max: {3} in units of: {4}'.
      format(d1.getDimensionId(), d1.getNBins(), d1.getMinimum(), d1.getMaximum(), d1.getUnits()))

Output:

created workspace is of type: MDHistoWorkspace
and has 2 dimensions with 100 points and 0 events
dimension 0 has ID: Dim1; nBins=10; min: -3.0; max: 3.0 in units of: MomentumTransfer
dimension 1 has ID: Dim2; nBins=10; min: -10.0; max: 10.0 in units of: EnergyTransfer

Categories: AlgorithmIndex | MDAlgorithms\Creation

Source

C++ header: CreateMDHistoWorkspace.h

C++ source: CreateMDHistoWorkspace.cpp