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