int QSchange_objcoef (QSprob p, int indx, double coef)

/* Change the objective coefficient of variable y to 5.0   */

int rval = 0;
int yindex;

/* Find the index of of y */

rval = QSget_column_index (p, "y", &yindex);
if (rval) {
    fprintf (stderr, "could not get index, error code %d\n", rval);
} else {
    if (yindex == -1) {
        printf ("y is not a variable in the problem\n");
    } else {
        rval = QSchange_objcoef (p, yindex, 5.0);
        if (rval) {
            fprintf (stderr, "could not change coef, error %d\n", rval);
        }
    }
}