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#include "cs.h"
/* C = A' */
cs *cs_transpose (const cs *A, csi values)
{
csi p, q, j, *Cp, *Ci, n, m, *Ap, *Ai, *w ;
double *Cx, *Ax ;
cs *C ;
if (!CS_CSC (A)) return (NULL) ; /* check inputs */
m = A->m ; n = A->n ; Ap = A->p ; Ai = A->i ; Ax = A->x ;
C = cs_spalloc (n, m, Ap [n], values && Ax, 0) ; /* allocate result */
w = cs_calloc (m, sizeof (csi)) ; /* get workspace */
if (!C || !w) return (cs_done (C, w, NULL, 0)) ; /* out of memory */
Cp = C->p ; Ci = C->i ; Cx = C->x ;
for (p = 0 ; p < Ap [n] ; p++) w [Ai [p]]++ ; /* row counts */
cs_cumsum (Cp, w, m) ; /* row pointers */
for (j = 0 ; j < n ; j++)
{
for (p = Ap [j] ; p < Ap [j+1] ; p++)
{
Ci [q = w [Ai [p]]++] = j ; /* place A(i,j) as entry C(j,i) */
if (Cx) Cx [q] = Ax [p] ;
}
}
return (cs_done (C, w, NULL, 1)) ; /* success; free w and return C */
}
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