35 lines
1.0 KiB
C
35 lines
1.0 KiB
C
#include "cs.h"
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/* remove duplicate entries from A */
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int cs_dupl (cs *A)
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{
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int i, j, p, q, nz = 0, n, m, *Ap, *Ai, *w ;
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double *Ax ;
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if (!CS_CSC (A)) return (0) ; /* 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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w = cs_malloc (m, sizeof (int)) ; /* get workspace */
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if (!w) return (0) ; /* out of memory */
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for (i = 0 ; i < m ; i++) w [i] = -1 ; /* row i not yet seen */
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for (j = 0 ; j < n ; j++)
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{
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q = nz ; /* column j will start at q */
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for (p = Ap [j] ; p < Ap [j+1] ; p++)
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{
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i = Ai [p] ; /* A(i,j) is nonzero */
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if (w [i] >= q)
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{
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Ax [w [i]] += Ax [p] ; /* A(i,j) is a duplicate */
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}
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else
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{
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w [i] = nz ; /* record where row i occurs */
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Ai [nz] = i ; /* keep A(i,j) */
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Ax [nz++] = Ax [p] ;
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}
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}
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Ap [j] = q ; /* record start of column j */
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}
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Ap [n] = nz ; /* finalize A */
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cs_free (w) ; /* free workspace */
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return (cs_sprealloc (A, 0)) ; /* remove extra space from A */
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}
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