SRC/cpivotgrowth.c File Reference

Computes the reciprocal pivot growth factor. More...

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

Functions
float	cPivotGrowth (int ncols, SuperMatrix *A, int *perm_c, SuperMatrix *L, SuperMatrix *U)

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Detailed Description

 -- SuperLU routine (version 2.0) --
 Univ. of California Berkeley, Xerox Palo Alto Research Center,
 and Lawrence Berkeley National Lab.
 November 15, 1997
 

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Function Documentation

float cPivotGrowth	(	int	ncols,
		SuperMatrix *	A,
		int *	perm_c,
		SuperMatrix *	L,
		SuperMatrix *	U
	)

 Purpose
 =======

 Compute the reciprocal pivot growth factor of the leading ncols columns
 of the matrix, using the formula:
     min_j ( max_i(abs(A_ij)) / max_i(abs(U_ij)) )

 Arguments
 =========

 ncols    (input) int
          The number of columns of matrices A, L and U.

 A        (input) SuperMatrix*
	    Original matrix A, permuted by columns, of dimension
          (A->nrow, A->ncol). The type of A can be:
          Stype = NC; Dtype = SLU_C; Mtype = GE.

 L        (output) SuperMatrix*
          The factor L from the factorization Pr*A=L*U; use compressed row 
          subscripts storage for supernodes, i.e., L has type: 
          Stype = SC; Dtype = SLU_C; Mtype = TRLU.

 U        (output) SuperMatrix*
	    The factor U from the factorization Pr*A*Pc=L*U. Use column-wise
          storage scheme, i.e., U has types: Stype = NC;
          Dtype = SLU_C; Mtype = TRU.