File: cs_ltsolve.c

package info (click to toggle)
suitesparse-metis 3.1.0-2
  • links: PTS, VCS
  • area: contrib
  • in suites: jessie, jessie-kfreebsd, wheezy
  • size: 36,560 kB
  • ctags: 7,484
  • sloc: ansic: 104,515; makefile: 5,984; fortran: 4,591; sh: 1,397; csh: 739; ruby: 603; perl: 219; sed: 164; awk: 18
file content (18 lines) | stat: -rw-r--r-- 468 bytes parent folder | download | duplicates (6) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
 
#include "cs.h"
/* solve L'x=b where x and b are dense.  x=b on input, solution on output. */
int cs_ltsolve (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 = n-1 ; j >= 0 ; j--)
    {
	for (p = Lp [j]+1 ; p < Lp [j+1] ; p++)
	{
	    x [j] -= Lx [p] * x [Li [p]] ;
	}
	x [j] /= Lx [Lp [j]] ;
    }
    return (1) ;
}