[GENERAL INFORMATION]
Function Name=Boltzmann
Brief Description=Boltzmann Function - produce a sigmoidal curve.
Function Source=fgroup.Boltzman
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=A1,A2,x0,dx
Meanings=init value,final value,center,time const
Lower Bounds=--(I,Off),--(I,Off),--(I,Off),(X,Off)
Upper Bounds=--(I,Off),--(I,Off),--(I,Off),--(I,Off)
Number Of Significant Digits=


[FORMULA]

y = A2 + (A1-A2)/(1 + exp((x-x0)/dx))


[CONSTRAINTS]

dx != 0


[CONSTANTS]



[Parameters Initialization]
sort(x_y_curve);
//smooth(x_y_curve, 2);
x0 = xaty50( x_y_curve );
double xmin, xmax;
x_data.GetMinMax(xmin, xmax);
dx = (xmax - xmin) / 20.0;
if( yatxmin( x_y_curve ) > yatxmax( x_y_curve ) )
{
  A1 = max( y_data );
  A2 = min( y_data );
}
else
{
  A1 = min( y_data );
  A2 = max( y_data );
}



[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

