SRC/ilu_cpivotL.c File Reference

Performs numerical pivoting. More...

#include <math.h>
#include <stdlib.h>
#include "slu_cdefs.h"

Defines
#define	SGN(x)   ((x)>=0?1:-1)
Functions
int	ilu_cpivotL (const int jcol, const double u, int *usepr, int *perm_r, int diagind, int *swap, int *iswap, int *marker, int *pivrow, double fill_tol, milu_t milu, complex drop_sum, GlobalLU_t *Glu, SuperLUStat_t *stat)

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Detailed Description

 -- SuperLU routine (version 4.0) --
 Lawrence Berkeley National Laboratory
 June 30, 2009
 

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Define Documentation

#define SGN

(

x

)

((x)>=0?1:-1)

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Function Documentation

int ilu_cpivotL	(	const int	jcol,
		const double	u,
		int *	usepr,
		int *	perm_r,
		int	diagind,
		int *	swap,
		int *	iswap,
		int *	marker,
		int *	pivrow,
		double	fill_tol,
		milu_t	milu,
		complex	drop_sum,
		GlobalLU_t *	Glu,
		SuperLUStat_t *	stat
	)

 Purpose
 =======
   Performs the numerical pivoting on the current column of L,
   and the CDIV operation.

   Pivot policy:
   (1) Compute thresh = u * max_(i>=j) abs(A_ij);
   (2) IF user specifies pivot row k and abs(A_kj) >= thresh THEN
	     pivot row = k;
	 ELSE IF abs(A_jj) >= thresh THEN
	     pivot row = j;
	 ELSE
	     pivot row = m;

   Note: If you absolutely want to use a given pivot order, then set u=0.0.

   Return value: 0	  success;
		   i > 0  U(i,i) is exactly zero.