1 #include "cs.h"
2 /* C = A' */
cs_transpose(const cs * A,CS_INT values)3 cs *cs_transpose (const cs *A, CS_INT values)
4 {
5 CS_INT p, q, j, *Cp, *Ci, n, m, *Ap, *Ai, *w ;
6 CS_ENTRY *Cx, *Ax ;
7 cs *C ;
8 if (!CS_CSC (A)) return (NULL) ; /* check inputs */
9 m = A->m ; n = A->n ; Ap = A->p ; Ai = A->i ; Ax = A->x ;
10 C = cs_spalloc (n, m, Ap [n], values && Ax, 0) ; /* allocate result */
11 w = cs_calloc (m, sizeof (CS_INT)) ; /* get workspace */
12 if (!C || !w) return (cs_done (C, w, NULL, 0)) ; /* out of memory */
13 Cp = C->p ; Ci = C->i ; Cx = C->x ;
14 for (p = 0 ; p < Ap [n] ; p++) w [Ai [p]]++ ; /* row counts */
15 cs_cumsum (Cp, w, m) ; /* row pointers */
16 for (j = 0 ; j < n ; j++)
17 {
18 for (p = Ap [j] ; p < Ap [j+1] ; p++)
19 {
20 Ci [q = w [Ai [p]]++] = j ; /* place A(i,j) as entry C(j,i) */
21 if (Cx) Cx [q] = (values > 0) ? CS_CONJ (Ax [p]) : Ax [p] ;
22 }
23 }
24 return (cs_done (C, w, NULL, 1)) ; /* success; free w and return C */
25 }
26