Lephisto/lib/csparse/cs_lsolve.c

19 lines
463 B
C

#include "cs.h"
/* solve Lx=b where x and b are dense. x=b on input, solution on output. */
int cs_lsolve (const cs *L, double *x)
{
int p, j, n, *Lp, *Li ;
double *Lx ;
if (!CS_CSC (L) || !x) return (0) ; /* check inputs */
n = L->n ; Lp = L->p ; Li = L->i ; Lx = L->x ;
for (j = 0 ; j < n ; j++)
{
x [j] /= Lx [Lp [j]] ;
for (p = Lp [j]+1 ; p < Lp [j+1] ; p++)
{
x [Li [p]] -= Lx [p] * x [j] ;
}
}
return (1) ;
}