19 lines
468 B
C
19 lines
468 B
C
#include "cs.h"
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/* solve L'x=b where x and b are dense. x=b on input, solution on output. */
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int cs_ltsolve (const cs *L, double *x)
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{
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int p, j, n, *Lp, *Li ;
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double *Lx ;
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if (!CS_CSC (L) || !x) return (0) ; /* check inputs */
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n = L->n ; Lp = L->p ; Li = L->i ; Lx = L->x ;
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for (j = n-1 ; j >= 0 ; j--)
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{
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for (p = Lp [j]+1 ; p < Lp [j+1] ; p++)
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{
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x [j] -= Lx [p] * x [Li [p]] ;
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}
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x [j] /= Lx [Lp [j]] ;
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}
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return (1) ;
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}
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