[General Information]

Function Name=LangmuirEXT1	; name show up in the select function dialog
Brief Description=extended Langmuir Model
Function Type=Built-in		; source type, built-in, user-defined, external dll
Function Form=Expression	; function form;
Function Source=fgroup.LangmuirEXT1
Number Of Parameters=3
Number Of Independent Variables=1
Number Of Dependent Variables=1


[Fitting Parameters]

Naming Method=user-defined
Names=a,b,c
Lower bounds=--,--,--
Upper bounds=--,--,--
Meanings=coefficient,coefficient,coefficient


[Independent Variables]

x = 


[Dependent Variables]

y = 


[Constants]


[Formula]

y = (a*b*x^(1-c))/(1 + b*x^(1-c))

[Constraints]

[Parameters Initialization]
sort(x_y_curve);
smooth(x_y_curve);
a=yatxmax(x_y_curve);
double x1=0.75*min(x_data)+0.25*max(x_data);
double y1=Curve_yfromX(&x_y_curve,x1);
double x2=0.25*min(x_data)+0.75*max(x_data);
double y2=Curve_yfromX(&x_y_curve,x2);
c=1-ln(y2*(a-y1)/(y1*(a-y2)))/ln(x2/x1);
b=exp(ln(y2/(a-y2))-(1-c)*ln(x2));

[Initializations]


[After fitting]


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

