Peakgaussian: Difference between revisions

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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
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* '''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,  .

Revision as of 16:34, 3 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