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IqtFitMultiple v1

Summary

Fits an *_iqt file generated by I(Q,t).

Properties

Name	Direction	Type	Default	Description
InputWorkspace	Input	MatrixWorkspace	Mandatory	The _iqt.nxs InputWorkspace used by the algorithm
Function	InOut	Function	Mandatory	The function to use in fitting
FitType	Input	string		The type of fit being carried out
StartX	Input	number	0	The first value for X
EndX	Input	number	0.2	The last value for X
SpecMin	Input	number	0	Minimum spectra in the workspace to fit
SpecMax	Input	number	1	Maximum spectra in the workspace to fit
Minimizer	Input	string	Levenberg-Marquardt	The minimizer to use in fitting
MaxIterations	Input	number	500	The Maximum number of iterations for the fit
ConstrainIntensities	Input	boolean	False	If the Intensities should be constrained during the fit
ExtractMembers	Input	boolean	False	If true, then each member of the fit will be extracted, into their own workspace. These workspaces will have a histogram for each spectrum (Q-value) and will be grouped.
OutputResultWorkspace	Output	MatrixWorkspace	Mandatory	The output workspace containing the results of the fit data
OutputParameterWorkspace	Output	TableWorkspace	Mandatory	The output workspace containing the parameters for each fit
OutputWorkspaceGroup	Output	WorkspaceGroup	Mandatory	The OutputWorkspace group Data, Calc and Diff, values for the fit of each spectra

Description

Fits an *_iqt file generated by Iqt using one of the specified functions. The functions available are either one or two exponentials (\(Intensity \times exp[-(x/\tau)]\)), a stretched exponential (\(Intensity \times exp[-(x/\tau)]\beta\)) or a combination of both an exponential and stretched exponential.

This routine was originally part of the MODES package.

Workflow

Usage

Example - Running IqtFitMultiple on an reduced workspace.

#Load in iqt data
input_ws = Load(Filename='iris26176_graphite002_iqt.nxs')
function = r'name=LinearBackground,A0=0.027668,A1=0,ties=(A1=0);name=UserFunction,Formula=Intensity*exp(-(x/Tau)^Beta),Intensity=0.972332,Tau=0.0247558,Beta=1;ties=(f1.Intensity=1-f0.A0)'

#run IqtFitMultiple
result, params, fit_group = IqtFitMultiple(InputWorkspace=input_ws, Function=function, FitType='1S_s', StartX=0, EndX=0.2, SpecMin=0, SpecMax=16)

Categories: AlgorithmIndex | Workflow\MIDAS

Source

Python: IqtFitMultiple.py