[General Information]

Function Name=PearsonVII	; name show up in the select function dialog
Brief Description=Pearson VII peak function
Function Type=Built-in		; source type, built-in, user-defined, external dll
Function Form=Expression	; function form;
Function Source=fgroup.PearsonVII
Number Of Parameters=4
Number Of Independent Variables=1
Number Of Dependent Variables=1


[Fitting Parameters]

Naming Method=user-defined
Names=xc,A,w,mu
Lower bounds=--,0.0(X,ON),0.0(X,ON),0.0(X,ON)
Upper bounds=--,--,--,--
Meanings=center,amplitude,width,profile shape factor


[Independent Variables]

x = 


[Dependent Variables]

y = 


[Constants]


[Parameters Initialization]
sort(x_y_curve);
smooth(x_y_curve);
w = 0.85 * fwhm( x_y_curve );
mu = 1.0;
A = area( x_y_curve );
if ( A > 0 ) xc = xatymax( x_y_curve );
else xc = xatymin( x_y_curve );



[Formula]

y = A * 2 * sqrt(mu) * exp(gammaln(2^(1./mu)-1)) / ( PI * w * exp(gammaln(mu - 0.5)) ) * ( 1. + 4. * (2^(1./mu)-1) / w^2 * (x - xc)^2 )^(-mu)

[Constraints]


[Initializations]


[After fitting]


[Controls]
General Linear Constraints=Off
Initialization scripts=Off
Scripts After fitting=Off

