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ImportMDEventWorkspace v1

Summary

Reads an ASCII file containing MDEvent data and constructs an MDEventWorkspace.

See Also

ImportMDHistoWorkspace

Properties

Name	Direction	Type	Default	Description
Filename	Input	string	Mandatory	File of type txt. Allowed extensions: [‘.txt’]
OutputWorkspace	Output	MDEventWorkspace	Mandatory	An output workspace.

Description

Creates an MDEventWorkspace from a plain ASCII file. Uses a simple format for the file described below. This algorithm is suitable for importing small volumes of data only. This algorithm does not scale well for large input workspaces. The purpose of this algorithm is to allow users to quickly import data from existing applications for purposes of comparison.

Format

The file must contain a DIMENSIONS section listing the dimensionality of the workspace. Each input line is taken as a new dimension after the DIMENSIONS flag, and before the MDEVENTS flag. Input arguments must be separated by a space or tab. They are provided in the order Name, ID, Units, NumberOfBins. See the Usage examples below.

The file must contain a MDEVENTS flag after the DIMENSIONS flag. Again, inputs are separated by a space or tab, each line represents a unique MDEvent. There must be either NDims + 2 or NDims + 4 columns in this section. If there are NDims + 2, columns, then Lean MDEvents will be used (Signal, Error and Dimensionality only). If there are NDims + 4 columns, then Full MDEvents will be used (Signal, Error, RunNo, DetectorId and Dimensionality). If you have provided NDims + 2 columns, then each row is interpreted as follows:

Signal Error {Dimensionality}

where the Dimensionality is an array of coordinates in each of the dimensions listed in the DIMENSIONS section, and in that order. IF there are NDims + 4 columns, then Full MDEvents will be used. Each row is interpreted as follows:

Signal Error RunNumber DetectorId {Dimensionality}

The usage example below shows demo files with both of these formats.

Comments are denoted by lines starting with #. There is no multi-line comment.

Alternatives

Other alternatives to importing/creating MDWorkspaces are ImportMDHistoWorkspace, CreateMDHistoWorkspace and CreateMDWorkspace

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 - MDLeanEvents

ws = ImportMDEventWorkspace("demo_mdew_mdleanevents.txt")
print("Number of Events = {}".format(ws.getNEvents()))
print("Workspace type = {}".format(ws.id()))

Output:

Number of Events = 20
Workspace type = MDEventWorkspace<MDLeanEvent,2>

Example - MDEvents

ws = ImportMDEventWorkspace("demo_mdew_mdevents.txt")
print("Number of Events = {}".format(ws.getNEvents()))
print("Workspace type = {}".format(ws.id()))

Output:

Number of Events = 20
Workspace type = MDEventWorkspace<MDEvent,2>

Categories: AlgorithmIndex | MDAlgorithms\DataHandling

Source

C++ header: ImportMDEventWorkspace.h

C++ source: ImportMDEventWorkspace.cpp