void _nlsfpch_PWR_c1_in_Origin_80(
// Fit Parameter(s):
double c, double q, double p,
// Independent Variable(s):
double x,
// Dependent Variable(s):
double& y)
{
	// Beginning of editable part
	Worksheet wks = Project.ActiveLayer();
	NLFitContext *pCtxt = Project.GetNLFitContext();
	if ( pCtxt )
	{
		// Hard coded, for user's dataset.
		double Ntot = 64;
		double Mtot = 499999;
		// Whether the paremeters are changed
		BOOL bIsNewParamValues = pCtxt->IsNewParamValues();
		// Static vector to hold results
		static vector vHist;
		vHist.SetSize(Ntot);
		// If parameters are changed, calculate vHist
		if ( bIsNewParamValues )
		{			
			int err=0;
			x = x*1.; // Make the compiler happy;
			
			// Initialization for the user define dll function
			vector<double> gRe(Ntot), gIm(Ntot);
			double cv[5], qv[5], BeamParam[12];
			
			for (int ii=0; ii<5; ii++) {
				cv[ii]=0;
				qv[ii]=0;
			}
			for (ii=0; ii<12; ii++) {
				BeamParam[ii]=0;
			}	
			cv[0] = c; qv[0] = q;
			
			BeamParam[0] = 0; BeamParam[1] = p;
			BeamParam[2] = 0;
			BeamParam[11] = 1;
			// End initialization for user define dll function.
			
			// The user define function, got Re and Im part of the complex vector
			err = intPCH(cv, qv, BeamParam, Ntot, gRe, gIm);
			NagError fail;
			// Perform fft
			nag_fft_complex(Ntot, gRe, gIm, &fail);
			// Calculate vHist;
			vHist = Mtot*gRe/sqrt(Ntot);			
		}
		
		// Use the data index to access y values
		// NLSFCURRINFO    stCurrInfo;
		// pCtxt->GetFitCurrInfo(&stCurrInfo);
		// int nCurrentIndex = stCurrInfo.nCurrDataIndex;
		// y = vHist[nCurrentIndex];
		// End Use the data index to access y values
		y = vHist[x]; // Got y value.
	}
	// End of editable part
}