Integration v1

../_images/Integration-v1_dlg.png

Integration dialog.

Summary

Integration takes a 2D workspace or an EventWorkspace as input and sums the data values. Optionally, the range summed can be restricted in either dimension.

Properties

Name Direction Type Default Description
InputWorkspace Input MatrixWorkspace Mandatory The input workspace to integrate.
OutputWorkspace Output MatrixWorkspace Mandatory The output workspace with the results of the integration.
RangeLower Input number Optional The lower integration limit (an X value).
RangeUpper Input number Optional The upper integration limit (an X value).
StartWorkspaceIndex Input number 0 Index of the first spectrum to integrate.
EndWorkspaceIndex Input number Optional Index of the last spectrum to integrate.
IncludePartialBins Input boolean False If true then partial bins from the beginning and end of the input range are also included in the integration.

Description

Integration sums up spectra in a Workspace and outputs a Workspace that contains only 1 value per spectrum (i.e. the sum). The associated errors are added in quadrature. The two X values per spectrum are set to the limits of the range over which the spectrum has been integrated. By default, the entire range is integrated and all spectra are included.

Optional properties

If only a portion of the workspace should be integrated then the optional parameters may be used to restrict the range. StartWorkspaceIndex & EndWorkspaceIndex may be used to select a contiguous range of spectra in the workspace (note that these parameters refer to the workspace index value rather than spectrum numbers as taken from the raw file). If only a certain range of each spectrum should be summed (which must be the same for all spectra being integrated) then the RangeLower and RangeUpper properties should be used. No rebinning takes place as part of this algorithm: if the values given do not coincide with a bin boundary then the first bin boundary within the range is used. If a value is given that is beyond the limit covered by the spectrum then it will be integrated up to its limit. The data that falls outside any values set will not contribute to the output workspace.

EventWorkspaces

If an EventWorkspace is used as the input, the output will be a MatrixWorkspace. Rebin v1 is recommended if you want to keep the workspace as an EventWorkspace.

Integration for event workspaces refers to internal binning, provided by :ref:`algm-Rebin` or load algorithm and may ignore limits, provided as algorithm input. For example, attempt to integrate loaded ISIS event workspace in the range [18000,20000] yields workspace integrated in the range [0,200000], assuming the data were collected in the time range [0,20000]. This happens because the event data would have single histogram workspace bin in range [0,20000]. To obtain integral in the desired range, user have to Rebin v1 first, and one of the binning intervals have to start from 18000 and another (or the same) end at 20000.

Usage

# Create a workspace filled with a constant value = 1.0
ws=CreateSampleWorkspace('Histogram','Flat background')
# Integrate 10 spectra over all X values
intg=Integration(ws,StartWorkspaceIndex=11,EndWorkspaceIndex=20)

# Check the result
print 'The result workspace has',intg.getNumberHistograms(),'spectra'
print 'Integral of spectrum',11,'is',intg.readY(0)[0]
print 'Integral of spectrum',12,'is',intg.readY(1)[0]
print 'Integral of spectrum',13,'is',intg.readY(2)[0]
print 'Integration range is [',intg.readX(0)[0],',',intg.readX(0)[1],']'

Output

The result workspace has 10 spectra
Integral of spectrum 11 is 100.0
Integral of spectrum 12 is 100.0
Integral of spectrum 13 is 100.0
Integration range is [ 0.0 , 20000.0 ]

Categories: Algorithms | Arithmetic | Transforms\Rebin

Source

C++ source: Integration.cpp

C++ header: Integration.h