ABACUS/src/FITTING/covsrt.cc

/**********************************************************

This software is part of J.-S. Caux's ABACUS library.

Copyright (c) J.-S. Caux.

-----------------------------------------------------------

File:  covsrt.cc

Purpose:  covsrt algorithm

***********************************************************/

#include "ABACUS.h"

using namespace std;

namespace ABACUS {

  void covsrt (SQMat_DP& covar, Vect<bool>& ia, const int mfit)
  {
    int i, j, k;

    int ma = ia.size();

    for (i = mfit; i < ma; i++)
      for (j = 0; j < i+1; j++) covar[i][j] = covar[j][i] = 0.0;
    k = mfit - 1;
    for (j = ma - 1; j >= 0; j--) {
      if (ia[j]) {
	for (i = 0; i < ma; i++) SWAP(covar[i][k], covar[i][j]);
	for (i = 0; i < ma; i++) SWAP(covar[k][i], covar[j][i]);
	k--;
      }
    }
  }

}