[GENERAL INFORMATION]
Function Name=GCAS
Brief Description=Gram-Charlier peak function for use in chromatography
Function Source=fgroup.GCAS
Function Type=Built-in
Function Form=Expression
Number Of Parameters=6
Number Of Independent Variables=1
Number Of Dependent Variables=1


[FITTING PARAMETERS]
Naming Method=User-Defined
Names=y0,xc,A,w,a3,a4
Meanings=offset,center,amplitude,width,unknown,unknown
Lower Bounds=--,--,--,0.0(X,ON),--,--
Upper Bounds=--,--,--,--,--,--
Number Of Significant Digits=


[FORMULA]

y = y0 + (A / (w * sqrt(2 * PI))) * exp( -((x-xc)/w)^2/2.) * (1 + (a3/6)*(((x-xc)/w)^3 - 3. * ((x-xc)/w)) + (a4/24)*( ((x-xc)/w)^4 - 6. * ((x-xc)/w)^3 + 3 ) )

[CONSTRAINTS]



[CONSTANTS]


[Parameters Initialization]
sort(x_y_curve);
smooth(x_y_curve);
y0 = yatxmin( x_y_curve );
w = 0.85 * fwhm( x_y_curve, y0 );
A = area( x_y_curve, y0 );
if ( A > 0 ) xc = xatymax( x_y_curve );
else xc = xatymin( x_y_curve );
a3 = 0.1;
a4 = 0.1;

[INITIALIZATIONS]



[AFTER FITTING]



[INDEPENDENT VARIABLES]
x=


[DEPENDENT VARIABLES]
y=


[CONTROLS]
General Linear Constraints=Off
Initialization Scripts=Off
Scripts After Fitting=Off
Number Of Duplicates=0
Duplicate Offset=2
Duplicate Unit=5
Generate Curves After Fitting=Yes
Curve Point Spacing=Uniform on X-Axis Scale
Generate Peaks After Fitting=Yes
Generate Peaks During Fitting=Yes
Generate Peaks with Baseline=Yes
Paste Parameters to Plot After Fitting=Yes
Paste Parameters to Script Window After Fitting=Yes
Generate Residue After Fitting=No
Keep Parameters=No


