[General Information]

Function Name=Harris	; name show up in the select function dialog
Brief Description=Farazdaghi-Harris Model for use in yield-density study
Function Type=Built-in		; source type, built-in, user-defined, external dll
Function Form=Expression	; function form;
Function Source=fgroup.Harris
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,power

[Independent Variables]

x = 


[Dependent Variables]

y = 


[Constants]


[Formula]

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

[Constraints]

[Parameters Initialization]
sort( x_y_curve );
smooth( x_y_curve );
x_y_curve = 1 / x_y_curve;
a = yatxmin( x_y_curve );
double flag = yatxmin( x_y_curve ) - yatxmax (x_y_curve );
if ( flag > 0 ) x_y_curve = ln( a - x_y_curve );
else x_y_curve = ln( x_y_curve - a );
Dataset dx;
x_y_curve.AttachX(dx);
dx = ln(dx);
double coeff[2];
fitpoly( x_y_curve, 1, coeff, 3, 3);
if ( flag > 0 ) b = -exp( coeff[0] );
else b = exp( coeff[0] );
c = coeff[1];

[Initializations]


[After fitting]


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

