[General Information]

Function Name=SGompertz 	; name show up in the select function dialog
Brief Description=Gompertz Growth Model for Popuplation Studies, Animal Growth.
Function Type=Built-in		; source type, built-in, user-defined, external dll
Function Form=Expression	; function form;
Function Source=fgroup.SGompertz
Number Of Parameters=3
Number Of Independent Variables=1
Number Of Dependent Variables=1


[Fitting Parameters]

Naming Method=user-defined
Names=a,xc,k
Lower bounds=0.0(X,ON),--,0.0(X,ON)
Upper bounds=--,--,--
Meanings=amplitude, center, coefficient

[Independent Variables]

x = 


[Dependent Variables]

y = 


[Constants]


[Formula]

y = a*exp(-exp(-k*(x-xc)))

[Constraints]


[Parameters Initialization]
sort( x_y_curve );
smooth( x_y_curve );
a = max(y_data);
x_y_curve = ln( x_y_curve );
x_y_curve = ln( ln(a) - x_y_curve );
double coeff[2];
fitpoly( x_y_curve, 1, coeff );
xc = -coeff[1] / coeff[0];
k = coeff[1] / xc;

[Initializations]


[After fitting]


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

