26 lines
789 B
C
26 lines
789 B
C
#include "cs.h"
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/* drop entries for which fkeep(A(i,j)) is false; return nz if OK, else -1 */
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int cs_fkeep (cs *A, int (*fkeep) (int, int, double, void *), void *other)
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{
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int j, p, nz = 0, n, *Ap, *Ai ;
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double *Ax ;
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if (!CS_CSC (A) || !fkeep) return (-1) ; /* check inputs */
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n = A->n ; Ap = A->p ; Ai = A->i ; Ax = A->x ;
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for (j = 0 ; j < n ; j++)
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{
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p = Ap [j] ; /* get current location of col j */
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Ap [j] = nz ; /* record new location of col j */
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for ( ; p < Ap [j+1] ; p++)
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{
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if (fkeep (Ai [p], j, Ax ? Ax [p] : 1, other))
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{
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if (Ax) Ax [nz] = Ax [p] ; /* keep A(i,j) */
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Ai [nz++] = Ai [p] ;
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}
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}
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}
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Ap [n] = nz ; /* finalize A */
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cs_sprealloc (A, 0) ; /* remove extra space from A */
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return (nz) ;
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}
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