// CSparse/Source/cs_gaxpy: sparse matrix times dense vector // CSparse, Copyright (c) 2006-2022, Timothy A. Davis. All Rights Reserved. // SPDX-License-Identifier: LGPL-2.1+ #include "cs.h" /* y = A*x+y */ csi cs_gaxpy (const cs *A, const double *x, double *y) { csi p, j, n, *Ap, *Ai ; double *Ax ; if (!CS_CSC (A) || !x || !y) return (0) ; /* check inputs */ n = A->n ; Ap = A->p ; Ai = A->i ; Ax = A->x ; for (j = 0 ; j < n ; j++) { for (p = Ap [j] ; p < Ap [j+1] ; p++) { y [Ai [p]] += Ax [p] * x [j] ; } } return (1) ; }