Peakgaussian: Difference between revisions
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===Description=== | ===Description=== | ||
Given a 3-element vector of parameters (x) and a vector of independent variables e.g. a wavelength or frequency axis (ax), PEAKGAUSSIAN outputs a Gaussian peak (y). If more than one output is requested, it also outputs the Jacobian (y1) and Hessian (y2). Derivatives are with respect to the parameters and are evaluated at (x). This function is called by PEAKFUNCTION. | Given a 3-element vector of parameters (x) and a vector of independent variables e.g. a wavelength or frequency axis (ax), PEAKGAUSSIAN outputs a Gaussian peak (y). If more than one output is requested, it also outputs the Jacobian (y1) and Hessian (y2). Derivatives are with respect to the parameters and are evaluated at (x). This function is called by PEAKFUNCTION. | ||
INPUTS | ====INPUTS==== | ||
* x = 3 element vector with parameters | * '''x''' = 3 element vector with parameters | ||
* x(1) = coefficient , | * '''x(1)''' = coefficient , | ||
* x(2) = mean , and | * '''x(2)''' = mean , and | ||
* x(3) = spread . | * '''x(3)''' = spread . | ||
* ax = vector of independent variables e.g. a wavelength or frequency axis with elements , . | * '''ax''' = vector of independent variables e.g. a wavelength or frequency axis with elements , . | ||
OUTPUTS | ====OUTPUTS==== | ||
* y = vector with the Gaussian function, . | * '''y''' = vector with the Gaussian function, . | ||
* y1 = matrix of the Jacobian of evaluated at (x). | * '''y1''' = matrix of the Jacobian of evaluated at (x). | ||
* y2 = matrix of the Hessian of evaluated at (x). | * '''y2''' = matrix of the Hessian of evaluated at (x). | ||
===Algorithm=== | ===Algorithm=== | ||
The function is | The function is | ||
Revision as of 19:57, 2 September 2008
Purpose
Outputs a Gaussian function, Jacobian, and Hessian for a given set of input parameters and axis.
Synopsis
- [y,y1,y2] = peakgaussian(x,ax)
Description
Given a 3-element vector of parameters (x) and a vector of independent variables e.g. a wavelength or frequency axis (ax), PEAKGAUSSIAN outputs a Gaussian peak (y). If more than one output is requested, it also outputs the Jacobian (y1) and Hessian (y2). Derivatives are with respect to the parameters and are evaluated at (x). This function is called by PEAKFUNCTION.
INPUTS
- x = 3 element vector with parameters
- x(1) = coefficient ,
- x(2) = mean , and
- x(3) = spread .
- ax = vector of independent variables e.g. a wavelength or frequency axis with elements , .
OUTPUTS
- y = vector with the Gaussian function, .
- y1 = matrix of the Jacobian of evaluated at (x).
- y2 = matrix of the Hessian of evaluated at (x).
Algorithm
The function is
Examples
- %Make a single known peak
- ax = 0:0.1:100;
- y = peakgaussian([2 51 8],ax);
- plot(ax,y)
See Also
peakfunction, peaklorentzian, peakpvoigt1, peakpvoigt2, peakstruct