2.2.1.2.17 NLFitSession::SetParamValues

SetParamValues

1 Description
2 Syntax
3 Parameters
4 Return
5 Examples
6 Remark
7 See Also
8 Header to Include

Description

Set all the paramter values. Before set parameter values need to set function and data firstly.

Syntax

int	SetParamValues(const vector& vParams)

Parameters

vParams: [input] contains all the parameters needed for the fit function.

Return

Return 0 if set successfully, -2 if fit function not ready, 1 if too few parameters, -1 if too many parameters.

Examples

EX1

Prior to running the following example, the nlsf_utils.c file need to be loaded and compiled. This can be done from script with the command run.LoadOC(Originlab\nlsf_utils.c) or just add this file to your workspace.
New a worksheet and import \Samples\Curve Fitting\Gaussian.dat.
Copy and compile the following codes, and run "NLFitSession_SetParamValues_ex1" in Command window.

#include <..\originlab\NLFitSession.h>
bool NLFitSession_SetParamValues_ex1()
{   
 	Worksheet wks = Project.ActiveLayer();
 	if( !wks )
 		return false;
 	
 	XYRange dr;
 	dr.Add(wks, 0, "X");
 	dr.Add(wks, 1, "Y");
 	dr.Add();
 	dr.Add(wks, 0, "X");
 	dr.Add(wks, 2, "Y");
 	
 	int 	nNumDataset = dr.GetNumData(DRR_GET_DEPENDENT); 
 	
 	vector 	vX1, vY1, vX2, vY2;
 	dr.GetData(vY1, vX1, NULL, 0);
 	dr.GetData(vY2, vX2, NULL, 1);
 
    NLFitSession    FitSession;
 
    // Set function
    if( !FitSession.SetFunction("Gauss")) // set function as Gauss, category name can be ignore
    {
        out_str("invalid fit function");
        return false;
    }   
 
    // Set first data
    if( !FitSession.SetData(vY1, vX1, NULL, 0, nNumDataset))
    {
        out_str("fail to set data");
        return false;
    }
    
    // Set second data
    if( !FitSession.SetData(vY2, vX2, NULL, 1, nNumDataset, DATA_MODE_GLOBAL))
    {
        out_str("fail to set data");
        return false;
    }

    // Set parameters
    vector vParams(8);
    // the parameters of the first dataset
    vParams[0] = 5.58; 		// y0
    vParams[1] = 26;		// xc
    vParams[2] = 8.66;		// w
    vParams[3] = 976;		// A
    
    // the parameters of the second dataset
    vParams[4] = 2.29; 	 	// y0
    vParams[5] = 26;		// xc
    vParams[6] = 10.32;		// w
    vParams[7] = 102.98;	// A
    
    if( 0 != FitSession.SetParamValues( vParams ) ) // return 0 if success
    {
    	out_str("fail to set parameters");
    	return false;
    }    
    FitSession.GetChiSqr(); // call GetChiSqr order to set parameter settings on internal fit object
 
    out_str("The parameter values before fitting");
    show_params(FitSession, nNumDataset);
 
    // Fit
    int     nOutcome;
    if( !FitSession.Fit(&nOutcome) )
    {
        out_str("Fail to do fitting");
        return false;
    }
    
    out_str("The parameter values after fitting");
    show_params(FitSession, nNumDataset);
 
    // Calculate fitting Y   
    vector      vFitY1(vX1.GetSize());
    if( 0 == FitSession.GetYFromX(vX1, vFitY1, vFitY1.GetSize(), 0) ) // get fitting y for first dataset
    {
        out_str("Fail to get Y values");
        return false;
    }
    
    vector      vFitY2(vX2.GetSize());
    if( 0 == FitSession.GetYFromX(vX2, vFitY2, vFitY2.GetSize(), 1) ) // get fitting y for second dataset
    {
        out_str("Fail to get Y values");
        return false;
    }

    // Add two columns to put fit data
    XYRange drFit;
    drFit.Add( wks, 0, "X" );
    drFit.Add( wks, wks.AddCol(), "Y");
    drFit.Add();
    drFit.Add( wks, 0, "X" );
    drFit.Add( wks, wks.AddCol(), "Y");
    
    drFit.SetData(&vFitY1, &vX1, 0);
    drFit.SetData(&vFitY2, &vX2, 1);  
 
    return true;
} 
 
void show_params(NLFitSession& FitSession, int nNumDataset)
{
    // get parameter values
    vector vParamValues, vErrors;
    FitSession.GetFitResultsParams(vParamValues, vErrors);    
 
    // get parameter names
    vector<string> vsParamNames;
    FitSession.GetParamNamesInFunction(vsParamNames);
    int nNumParamsInFunction = vsParamNames.GetSize();
 
    // output parameter values with names
    for(int nParam = 0; nParam < vParamValues.GetSize(); nParam++)
	{   
		int nDataset = nParam / nNumParamsInFunction;
		printf("Dataset %d\t%s = %f\n", nDataset + 1, vsParamNames[nParam % nNumParamsInFunction], vParamValues[nParam]);
	}
}