ReadGroupsFromFile v1#

Summary#

Read a diffraction calibration file (.cal) or an XML grouping file (.xml) and an instrument name, and output a 2D workspace containing on the Y-axis the values of the Group each detector belongs to. This is used to visualise the grouping scheme for powder diffractometers, where a large number of detectors are grouped together. The output 2D workspace can be visualize using the show instrument method.

See Also#

CreateDummyCalFile, CreateCalFileByNames, DiffractionFocussing, LoadCalFile, SaveCalFile, MergeCalFiles

Properties#

Name

Direction

Type

Default

Description

InstrumentWorkspace

Input

MatrixWorkspace

Mandatory

A workspace that refers to the instrument of interest. You can use [[LoadEmptyInstrument]] to create such a workspace.

GroupingFileName

Input

string

Mandatory

Either as a XML grouping file (see [[GroupDetectors]]) or as a [[CalFile]] (.cal extension). Allowed extensions: [‘.cal’, ‘.xml’]

ShowUnselected

Input

string

True

Whether to show detectors that are not in any group. Allowed values: [‘True’, ‘False’]

OutputWorkspace

Output

Workspace2D

Mandatory

The name of the output workspace

Description#

Instrument view of grouping using ReadFromFile with ShowUnselected=True All of the detectors in each group are given the a value equal to that of the group number. Unselected detectors are given a value of 0 if ShowUnselected is true.

The instrumentView is the best way to visualize the grouping using the “show Instrument” context menu option on the output workspace.

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 - Read 9 groups for INES instrument:

# Create workspace with INES instrument in it
ws1 = Load("INES_Definition.xml")

# Run algorithm
ws2 = ReadGroupsFromFile( ws1, "INES_example.cal")

# Print the value of selected sprectra. Each corresponds to the group of the corresponding detector.
for i in range(9):
    print(" ".join(str(ws2.readY(16 * i + j)) for j in range(0, 20, 5)))

Output:

[1.] [1.] [1.] [1.]
[2.] [2.] [2.] [2.]
[3.] [3.] [3.] [3.]
[4.] [4.] [4.] [4.]
[5.] [5.] [5.] [5.]
[6.] [6.] [6.] [6.]
[7.] [7.] [7.] [7.]
[8.] [8.] [8.] [8.]
[9.] [9.] [9.] [9.]

Categories: AlgorithmIndex | Diffraction\DataHandling\CalFiles

Source#

C++ header: ReadGroupsFromFile.h

C++ source: ReadGroupsFromFile.cpp