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// 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) ;
}
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