[GENERAL INFORMATION]
Function Name=Shah
Brief Description=Shah Model
Function Source=fgroup.Shah
Function Type=Built-in
Function Form=Expression
Number Of Parameters=4
Number Of Independent Variables=1
Number Of Dependent Variables=1


[FITTING PARAMETERS]
Naming Method=User-Defined
Names=a, b, c, r
Meanings=offset,coefficient, coefficient, ?
Lower Bounds=--,--,--,0.0(X,ON)
Upper Bounds=--,--,--,1.0(X,ON)
Number Of Significant Digits=


[FORMULA]

y = a + b*x + c*r^x


[CONSTRAINTS]

0<r<1

[Parameters Initialization]
sort( x_y_curve );
smooth( x_y_curve );
double coeff[2];
fitpoly( x_y_curve, 1, coeff, 3, 3);
a = coeff[0];
b = coeff[1];  
x_y_curve = ln( x_y_curve );
fitpoly( x_y_curve, 1, coeff, 1, 3);  
c = exp( coeff[1] );
r = 0.5;

[CONSTANTS]


[INITIALIZATIONS]



[AFTER FITTING]



[INDEPENDENT VARIABLES]
x=


[DEPENDENT VARIABLES]
y=


[CONTROLS]
General Linear Constraints=Off
Initialization Scripts=Off
Scripts After Fitting=Off
Number Of Duplicates=N/A
Duplicate Offset=N/A
Duplicate Unit=N/A


