starpu-max/examples/pastix-wrappers/models/num_recipes/covsrt.c

#define REAL double
#define SWAP(a,b) {swap=(a);(a)=(b);(b)=swap;}

void covsrt(REAL **covar, int ma, int ia[], int mfit)
{
	int i,j,k;
	REAL swap;

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