Fit on multiple datasets with one function with parameters shared

Version Info

Minimum Origin Version Required: Origin 8 SR0

Examples

Fit on two datasets with Gauss function, parameter xc is shared.

// before running this function, import \Samples\Curve Fitting\Gaussian.dat to worksheet.

#include <Origin.h>
#include <FDFTree.h>
#include <ONLSF.h>

void       NLFit_example2()
{
        string                  strFDF = okutil_get_origin_path(ORIGIN_PATH_SYSTEM, "FitFunc") + "Gauss.FDF";
        Tree                    trFF;
        if( !nlsf_FDF_to_tree( strFDF, &trFF ))
        {
                out_str("Fail to load FDF function file");
                return;
        }
        
        //////////////////////////////////////////////////////////////////////////////
        // 1. Setting the fitting function  //
        
        // The fit object:
        NLFit                   fit;
        int                                nn = fit.SetFunction(trFF);
        if (nn <= 0)
        {
                out_str("Failed setting fitting function!");
                return;
        }
        
        
        ///////////////////////////////////////////////////////////////////////////
        // 2. Setting data for fitting ////////////////////////////////////////////
        Worksheet       wks = Project.ActiveLayer();
        if( !wks )
        {
                out_str("No active worksheet to get input data");
                return;
        }
        
        DataRange       dr;
        dr.Add(wks, 0, "X");
        dr.Add(wks, 1, "Y");
        dr.Add();
        dr.Add(wks, 0, "X");
        dr.Add(wks, 2, "Y");
        
        DWORD           dwRules = DRR_GET_DEPENDENT | DRR_NO_FACTORS;
        int                nNumData = dr.GetNumData(dwRules);
        ASSERT( 2 == nNumData );
        if( nNumData <= 0 || nNumData > 2)
        {
                out_str("Not proper input data to do fit");
                return;    
        }
        
        NLSFONEDATA             stDep[2], stIndep[2];
        
        DWORD                   dwPlotID;
        vector                  vX1, vY1;
        dr.GetData( dwRules, 0, &dwPlotID, NULL, &vY1, &vX1);       
        stIndep[0].pdData = vX1;
        stIndep[0].nSize = vX1.GetSize();
        stDep[0].pdData = vY1;
        stDep[0].nSize = vY1.GetSize();

        
        vector                  vX2, vY2;
        dr.GetData( dwRules, 1, &dwPlotID, NULL, &vY2, &vX2);       
        stIndep[1].pdData = vX2;
        stIndep[1].nSize = vX2.GetSize();
        stDep[1].pdData = vY2;
        stDep[1].nSize = vY2.GetSize();
        
        
        nn = fit.SetData(nNumData, &stDep, &stIndep);
        if (nn != 0)
        {
                out_str("SetData() failed!");
                return;
        }     

        ///////////////////////////////////////////////////////////////////////////
        // 3. Set the initial paramater values and the sharing information/////////
        int                                numParamsInFunction = 4;              // there are this many paramaters in the function. y0, xc, W, A   
        int                                nTotalParams = nNumData * numParamsInFunction;
        int                                nNumParamsIgnoreShared = nTotalParams - 1; 
        
        vector<int>        vbSharing;
        vbSharing.SetSize(nNumParamsIgnoreShared);
        vbSharing = 0;
        vbSharing[1] = 1; //xc shared

        vector                  vFitParams;
        vFitParams.SetSize(nNumParamsIgnoreShared);
        vFitParams[0] = 5.58;  //y0 for 1st data
        vFitParams[1] = 26;            //xc shared for 1st data and 2nd data
        vFitParams[2] = 8.6;   // W for 1st data
        vFitParams[3] = 976;   // A for 1st data
        vFitParams[4] = 2.4;   // y0 for 2nd data
        vFitParams[5] = 9.8;    // W for 2nd data
        vFitParams[6] = 95;            // A for 2nd data

        
        nn = fit.SetParams(nNumParamsIgnoreShared, vFitParams, vbSharing);
        out_int("SetParams() returned: ", nn);
        if ( 0 != nn )
        {
                out_str("Invalid paramater setting!");
                return;
        }
        
        
        ///////////////////////////////////////////////////////////////////////////
        // 4. Perform fitting//////////////////////////////////////////////////////
        int                                nMaxNumIterations = 100;
        nn = fit.Fit(nMaxNumIterations);
        printf("Fit(%ld) returned: %ld\n", nMaxNumIterations, nn);
        if( 0 == nn )
                printf("Fit Done!\n");
        
        // Dump results:
        for (int iparam = 0; iparam < nNumParamsIgnoreShared; iparam++)
        {
                printf("param index = %d   value  value is = %lf\n", iparam + 1, vFitParams[iparam]);
        }
        
        return;
}