/* @(#)mo_mrqcof.c	17.1.1.1 (ES0-DMD) 01/25/02 17:49:06 */
/*===========================================================================
  Copyright (C) 1995 European Southern Observatory (ESO)
 
  This program is free software; you can redistribute it and/or 
  modify it under the terms of the GNU General Public License as 
  published by the Free Software Foundation; either version 2 of 
  the License, or (at your option) any later version.
 
  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
 
  You should have received a copy of the GNU General Public 
  License along with this program; if not, write to the Free 
  Software Foundation, Inc., 675 Massachusetss Ave, Cambridge, 
  MA 02139, USA.
 
  Corresponding concerning ESO-MIDAS should be addressed as follows:
	Internet e-mail: midas@eso.org
	Postal address: European Southern Observatory
			Data Management Division 
			Karl-Schwarzschild-Strasse 2
			D 85748 Garching bei Muenchen 
			GERMANY
===========================================================================*/

/* @(#)mo_mrqcof.c	17.1.1.1 (ESO-SDAG) 01/25/02 17:49:06 */
void MO_MRQCOF(x,y,sig,ndata,a,ma,lista,mfit,alpha,beta,chisq,funcs)
float  x[],y[];
float  sig[],a[];
float  **alpha,beta[];
float  *chisq;

int    ndata,ma,lista[],mfit;
void   (*funcs)();
                 /* ANSI: void (*funcs)(float,float *,float *,float *,int); */
{
	int k,j,i;
	float ymod,wt,sig2i,dy,*dyda;

	dyda=(float *) osmmget(ma * sizeof(float));
	for (j = 1; j <= mfit; j++) {
	   for (k=1; k<=j; k++) alpha[j][k] = 0.0;
	      beta[j]=0.0;
	}
	*chisq = 0.0;
	for (i = 1; i <= ndata; i++) {
	   (*funcs) (x[i],a,&ymod,dyda,ma);
	   sig2i = 1.0/(sig[i]*sig[i]);
	   dy    = y[i]-ymod;
	   for (j = 1; j <= mfit; j++) {
              wt = dyda[lista[j]]*sig2i;
              for (k = 1; k <= j; k++)
                 alpha[j][k] += wt*dyda[lista[k]];
	      beta[j] += dy*wt;
	   }
		
           (*chisq) += dy*dy*sig2i;
	}
	
        for (j = 2; j <= mfit; j++)
	   for (k = 1; k <= j-1; k++) alpha[k][j]=alpha[j][k];
	osmmfree((char *) dyda);
}