File: cs_usolve.c

package info (click to toggle)
suitesparse 1%3A5.8.1%2Bdfsg-2
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 152,716 kB
  • sloc: ansic: 774,385; cpp: 24,213; makefile: 6,310; fortran: 1,927; java: 1,826; csh: 1,686; ruby: 725; sh: 535; perl: 225; python: 209; sed: 164; awk: 60
file content (18 lines) | stat: -rw-r--r-- 519 bytes parent folder | download | duplicates (5) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
 
#include "cs.h"
/* solve Ux=b where x and b are dense.  x=b on input, solution on output. */
csi cs_usolve (const cs *U, double *x)
{
    csi p, j, n, *Up, *Ui ;
    double *Ux ;
    if (!CS_CSC (U) || !x) return (0) ;                     /* check inputs */
    n = U->n ; Up = U->p ; Ui = U->i ; Ux = U->x ;
    for (j = n-1 ; j >= 0 ; j--)
    {
        x [j] /= Ux [Up [j+1]-1] ;
        for (p = Up [j] ; p < Up [j+1]-1 ; p++)
        {
            x [Ui [p]] -= Ux [p] * x [j] ;
        }
    }
    return (1) ;
}