File: cs_pinv.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 (11 lines) | stat: -rw-r--r-- 402 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
#include "cs.h"
/* pinv = p', or p = pinv' */
int *cs_pinv (int const *p, int n)
{
    int k, *pinv ;
    if (!p) return (NULL) ;			/* p = NULL denotes identity */
    pinv = cs_malloc (n, sizeof (int)) ;	/* allocate result */
    if (!pinv) return (NULL) ;			/* out of memory */
    for (k = 0 ; k < n ; k++) pinv [p [k]] = k ;/* invert the permutation */
    return (pinv) ;				/* return result */
}