cs_pinv.c
Go to the documentation of this file.00001 #include "cs.h" 00002 /* pinv = p', or p = pinv' */ 00003 int *cs_pinv (int const *p, int n) 00004 { 00005 int k, *pinv ; 00006 if (!p) return (NULL) ; /* p = NULL denotes identity */ 00007 pinv = cs_malloc (n, sizeof (int)) ; /* allocate result */ 00008 if (!pinv) return (NULL) ; /* out of memory */ 00009 for (k = 0 ; k < n ; k++) pinv [p [k]] = k ;/* invert the permutation */ 00010 return (pinv) ; /* return result */ 00011 }