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LoadIDFFromNexus v1

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Summary

Load an IDF from a Nexus file, if found there. You may need to tell this algorithm where to find the Instrument folder in the Nexus file

Properties

Name	Direction	Type	Default	Description
Workspace	InOut	MatrixWorkspace	Mandatory	The name of the workspace in which to attach the imported instrument
Filename	Input	string	Mandatory	The name (including its full or relative path) of the Nexus file to attempt to load the instrument from. Allowed extensions: [‘.nxs’, ‘.nxs.h5’]
InstrumentParentPath	Input	string		Path name within the Nexus tree of the folder containing the instrument folder. For example it is ‘raw_data_1’ for an ISIS raw Nexus file and ‘mantid_workspace_1’ for a processed nexus file. Only a one level path is curently supported
ParameterCorrectionFilePath	Input	string		Full path name of Parameter Correction file. This should only be used in a situation,where the default full file path is inconvenient.

Description

Some Nexus files contain an instrument definition. This algorithm loads the instrument from this definition. You may need to tell this algorithm where in the Nexus file to find the Instrument folder that contains the instrument definition.

It also looks to see if it contains a separate instrument parameter map. If yes this is loaded. If no, the algorithm will attempt to load on parameter file on your disk from your instrument folder with the name INST_Parameters.xml. This may be overridden by a parameter correction file, which can be used to correct out of date embedded parameters.

A parameter correction file contains a list of parameter files, each with a non-overlapping date range and an append flag. If a parameter correction file is found, its list is compared to the workspace’s run start date. If this date occurs within one of the date ranges, the file with that date range is used as the parameter file. This parameter file must be in the same directory as the correction file. If the append flag is true this parameter file is used in addition to any other parameters that would be used, else it replaces the those parameters.

Notifications are displayed to inform, what the algorithm is doing.

Usage

Example - Load an IDF with differently named component

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.

result = Load("MUSR00015189")
group = result[0]
ws_1 = group[0]
ws_2 = group[1]

# musr_with_namechange.nxs has component named 'the rings' instead of 'both rings')
LoadIDFFromNexus(ws_1, "musr_with_namechange.nxs","/mantid_workspace_1")

# This workspace had the IDF loaded into it, so getting component renamed to "the rings".
inst1 = ws_1.getInstrument()
comp1 = inst1.getComponentByName("the rings")
print("Modified component name = {}".format(comp1.getName()))

# This workspace had no IDF loaded into it, so still has component named to "both rings".
inst2 = ws_2.getInstrument()
comp2 = inst2.getComponentByName("both rings")
print("Unmodified component name = {}".format(comp2.getName()))

Output:

Modified component name = the rings
Unmodified component name = both rings

Categories: AlgorithmIndex | DataHandling\Instrument

Source

C++ header: LoadIDFFromNexus.h

C++ source: LoadIDFFromNexus.cpp