dgstrs.c File Reference

Solves a system using LU factorization. More...

#include "slu_ddefs.h"

Include dependency graph for dgstrs.c:

Functions
void	dusolve (int, int, double *, double *)
	Solves a dense upper triangular system. More...
void	dlsolve (int, int, double *, double *)
	Solves a dense UNIT lower triangular system. More...
void	dmatvec (int, int, int, double *, double *, double *)
	Performs a dense matrix-vector multiply: Mxvec = Mxvec + M * vec. More...
void	dgstrs (trans_t trans, SuperMatrix *L, SuperMatrix *U, int *perm_c, int *perm_r, SuperMatrix *B, SuperLUStat_t *stat, int *info)
void	dprint_soln (int n, int nrhs, double *soln)

Detailed Description

Copyright (c) 2003, The Regents of the University of California, through Lawrence Berkeley National Laboratory (subject to receipt of any required approvals from U.S. Dept. of Energy)

All rights reserved.

The source code is distributed under BSD license, see the file License.txt at the top-level directory.

– SuperLU routine (version 3.0) –
Univ. of California Berkeley, Xerox Palo Alto Research Center,
and Lawrence Berkeley National Lab.
October 15, 2003

Copyright (c) 1994 by Xerox Corporation.  All rights reserved.

THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY
EXPRESSED OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.

Permission is hereby granted to use or copy this program for any
purpose, provided the above notices are retained on all copies.
Permission to modify the code and to distribute modified code is
granted, provided the above notices are retained, and a notice that
the code was modified is included with the above copyright notice.

Function Documentation

void dgstrs	(	trans_t	trans,
		SuperMatrix *	L,
		SuperMatrix *	U,
		int *	perm_c,
		int *	perm_r,
		SuperMatrix *	B,
		SuperLUStat_t *	stat,
		int *	info
	)

Purpose

DGSTRS solves a system of linear equations A*X=B or A'*X=B
with A sparse and B dense, using the LU factorization computed by
DGSTRF.

See supermatrix.h for the definition of 'SuperMatrix' structure.

Arguments

trans   (input) trans_t
         Specifies the form of the system of equations:
         = NOTRANS: A * X = B  (No transpose)
         = TRANS:   A'* X = B  (Transpose)
         = CONJ:    A**H * X = B  (Conjugate transpose)

L       (input) SuperMatrix*
        The factor L from the factorization Pr*A*Pc=L*U as computed by
        dgstrf(). Use compressed row subscripts storage for supernodes,
        i.e., L has types: Stype = SLU_SC, Dtype = SLU_D, Mtype = SLU_TRLU.

U       (input) SuperMatrix*
        The factor U from the factorization Pr*A*Pc=L*U as computed by
        dgstrf(). Use column-wise storage scheme, i.e., U has types:
        Stype = SLU_NC, Dtype = SLU_D, Mtype = SLU_TRU.

perm_c  (input) int*, dimension (L->ncol)
        Column permutation vector, which defines the 
        permutation matrix Pc; perm_c[i] = j means column i of A is 
        in position j in A*Pc.

perm_r  (input) int*, dimension (L->nrow)
        Row permutation vector, which defines the permutation matrix Pr; 
        perm_r[i] = j means row i of A is in position j in Pr*A.

B       (input/output) SuperMatrix*
        B has types: Stype = SLU_DN, Dtype = SLU_D, Mtype = SLU_GE.
        On entry, the right hand side matrix.
        On exit, the solution matrix if info = 0;

stat     (output) SuperLUStat_t*
         Record the statistics on runtime and floating-point operation count.
         See util.h for the definition of 'SuperLUStat_t'.

info    (output) int*
           = 0: successful exit
        < 0: if info = -i, the i-th argument had an illegal value

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void dlsolve	(	int	ldm,
		int	ncol,
		double *	M,
		double *	rhs
	)

The unit lower triangular matrix is stored in a 2D array M(1:nrow,1:ncol). The solution will be returned in the rhs vector.

void dmatvec	(	int	ldm,
		int	nrow,
		int	ncol,
		double *	M,
		double *	vec,
		double *	Mxvec
	)

The input matrix is M(1:nrow,1:ncol); The product is returned in Mxvec[].

void dprint_soln	(	int	n,
		int	nrhs,
		double *	soln
	)

void dusolve	(	int	ldm,
		int	ncol,
		double *	M,
		double *	rhs
	)

The upper triangular matrix is stored in a 2-dim array M(1:ldm,1:ncol). The solution will be returned in the rhs vector.