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MatrixWorkspace Attributes

Spectra and Bins

A MatrixWorkspace is a 2D array of data divided into spectra and bins.

Get the number of histograms (spectra) in a workspace:

print(workspace_name.getNumberHistograms())

Get the number of bins:

print(workspace_name.blocksize())

Read or Extract Data

Access the data using readX,Y,E (simply a view into an existing workspace) or extractX,Y,E (creates a copy of the data). These commands take a workspace index and returns a list of the relevant data.

Create a view of the Y data from the 2nd spectrum:

y_data2 = raw_workspace.readY(1)

for y in y_data2:
    print(y)

Workspace Objects

There is a lot of information about workspaces that can be accessed.

Below is a brief overview of the most commonly used functionality, for further details see:

• An exhaustive list

• A wider explanation

getSpectrum for info on the structure of a workspace eg. the spectrum number related to workspace index 0:

ws.getSpectrum(0).getSpectrumNo()

getAxis for Workspace labels and structure eg. Give the AxisUnit a new label:

ws.getAxis(0).getUnit().setLabel("Time-of-flight", "Milliseconds")

getInstrument for Sample and Source Geometry.

instrument = ws.getInstrument()
print(instrument.getName())

SpectrumInfo, DetectorInfo and ComponentInfo have many other features:

info = ws.spectrumInfo()
print(info.hasDetectors(0))

Useful links

• Working with Workspaces in Python

• Matrix Workspace

• mantid.api

• Concepts