Gaussian1D

From MantidProject

Contents 1 Deprecation notice 2 Summary 3 Properties 4 Source Code

Deprecation notice

Instead of using this algorithm to fit a Gaussian please use the Fit algorithm where the Function parameter of this algorithm is used to specified the fitting function, including selecting a Gaussian.

Summary

Takes a histogram in a 2D workspace and fit it to a Gaussian function (also called a normal distribution), i.e. to the function:

where

• BG0 - intercept of linear background
• BG1 - slope of linear background
• Height - height of peak
• PeakCentre - centre of peak
• Sigma - Gaussian width parameter

Note that the FWHM (Full Width Half Maximum) of a Gaussian equals .

Note that version 2 (the default version) of the Gaussian algorithm is described here. Version 1 is the same except that it only has one background (BG0) parameter, which is a constant, flat background.

The figure below illustrate this symmetric peakshape function fitted to a TOF peak:

Properties

Order	Name	Direction	Type	Default	Description
1	InputWorkspace	Input	Workspace	Mandatory	The name of the input Workspace
2	SpectrumIndex	Input	integer	0	The spectrum to fit, using the workspace numbering of the spectra (default 0)
3	StartX	Input	double	minus 6*sigma away from the peakCentre	X value to start fitting from
4	EndX	Input	double	plus 6*sigma away from the peakCentre	Last X value to include in fitting range
5	BG0	InOut	double	0.0	Intercept of linear background
6	BG1	InOut	double	0.0	Slope of linear background
7	Height	InOut	double	0.0	Height of peak
8	PeakCentre	InOut	double	0.0	Centre of peak
9	Sigma	InOut	double	1.0	Width parameter
10	Fix	Input	string	""	List of comma separated names of fit parameters to be fixed
11	MaxIterations	Input	Integer	500	Max iterations
12	Output Status	Output	String	""	Whether the fit was successful
13	Output Chi^2/DoF	Output	double	0.0	Returns the goodness of the fit

Source Code

Header Gaussian1D.h

Source Gaussian1D.cpp