4.2

CreateGroupingWorkspace v1

../_images/CreateGroupingWorkspace-v1_dlg.png

CreateGroupingWorkspace dialog.

Summary

Creates a new GroupingWorkspace using an instrument from one of: an input workspace, an instrument name, or an instrument IDF file. Optionally uses bank names to create the groups.

Properties

Name Direction Type Default Description
InputWorkspace Input MatrixWorkspace   Optional: An input workspace with the instrument we want to use.
InstrumentName Input string   Optional: Name of the instrument to base the GroupingWorkspace on which to base the GroupingWorkspace.
InstrumentFilename Input string   Optional: Path to the instrument definition file on which to base the GroupingWorkspace. Allowed extensions: [‘.xml’]
OldCalFilename Input string   Optional: Path to the old-style .cal grouping/calibration file (multi-column ASCII). You must also specify the instrument. Allowed extensions: [‘.cal’]
GroupNames Input string   Optional: A string of the instrument component names to use as separate groups. Use / or , to separate multiple groups. If empty, then an empty GroupingWorkspace will be created.
GroupDetectorsBy Input string   Only used if GroupNames is empty. Allowed values: [‘’, ‘All’, ‘Group’, ‘2_4Grouping’, ‘Column’, ‘bank’]
MaxRecursionDepth Input number 5 Number of levels to search into the instrument (default=5)
FixedGroupCount Input number 0 Used to distribute the detectors of a given component into a fixed number of groups
ComponentName Input string   Specify the instrument component to group into a fixed number of groups
OutputWorkspace Output GroupingWorkspace   An output GroupingWorkspace.
NumberGroupedSpectraResult Output number   The number of spectra in groups
NumberGroupsResult Output number   The number of groups

Description

A GroupingWorkspace is a simple workspace with one value per detector pixel; this value corresponds to the group number that will be used when focussing or summing another workspace.

This algorithm creates a blank GroupingWorkspace. It uses the InputWorkspace, InstrumentName, OR InstrumentFilename parameter to determine which Instrument to create.

If the OldCalFilename parameter is given, the .cal ASCII file will be loaded to fill the group data.

If the GroupNames parameter is given, the names of banks matching the comma-separated strings in the parameter will be used to sequentially number the groups in the output.

If both the FixedGroupCount and ComponentName parameter are given then the detectors for the given component will be grouped into the number of groups specified, detectors will be left ungrouped in the event that the number of detectors does not divide equally into the number of groups.

GroupDetectorsBy has five options

  • All create one group for the whole instrument
  • bank Creates one group per instrument component that starts with the word bank
  • Group Creates one group per instrument component that starts with the word Group. POWGEN will create groups for North and South. SNAP will create groups for East and West.
  • Column Creates one group per instrument component that starts with the word Column
  • 2_4Grouping (SNAP only) creates one group of 4 columns of SNAP detectors and another with the remaining 2 columns. This grouping is used frequently in their reduction.

Usage

Example - CreateGroupingWorkspace for MUSR Instrument

Note

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

# Run algorithm with instrument specified
result = CreateGroupingWorkspace(InstrumentName="MUSR")

# Confirm instrument in grouping workspace.
grouping = result[0]
inst1 = grouping.getInstrument()
comp1 = inst1.getComponentByName("MUSR")
print("Instrument name = {}".format(comp1.getName()))

Output:

Instrument name = MUSR

Example - CreateGroupingWorkspace from MUSR workspace

# Create Workspace
load_result = Load("MUSR00015189")
group = load_result[0]
ws_1 = group[0]

# Run algorithm with workspace
result = CreateGroupingWorkspace(InputWorkspace=ws_1)

# Confirm instrument in grouping workspace.
grouping = result[0]
inst1 = grouping.getInstrument()
comp1 = inst1.getComponentByName("MUSR")
print("Instrument name = {}".format(comp1.getName()))

Output:

Instrument name = MUSR

Example - CreateGroupingWorkspace from GEM Instrument Definition

# Run algorithm with Instrument Definition File
result = CreateGroupingWorkspace(InstrumentFilename="GEM_Definition.xml")

# Confirm instrument in grouping workspace.
grouping = result[0]
inst1 = grouping.getInstrument()
comp1 = inst1.getComponentByName("GEM")
print("Instrument name = {}".format(comp1.getName()))

Output:

Instrument name = GEM

Example - CreateGroupingWorkspace for IRIS graphite component

grouping_ws, spectra_count, group_count = CreateGroupingWorkspace(InstrumentName='IRIS', ComponentName='graphite', FixedGroupCount=5)

print("Number of grouped spectra: {}".format(spectra_count))
print("Number of groups: {}".format(group_count))

Output:

Number of grouped spectra: 50
Number of groups: 5

Categories: AlgorithmIndex | Utility\Workspaces | Transforms\Grouping

Source

C++ source: CreateGroupingWorkspace.cpp (last modified: 2019-06-05)

C++ header: CreateGroupingWorkspace.h (last modified: 2018-10-05)