SRC/sgstrs.c File Reference

Solves a system using LU factorization. More...

#include "slu_sdefs.h"

Functions
void	susolve (int, int, float *, float *)
	Solves a dense upper triangular system.
void	slsolve (int, int, float *, float *)
	Solves a dense UNIT lower triangular system.
void	smatvec (int, int, int, float *, float *, float *)
	Performs a dense matrix-vector multiply: Mxvec = Mxvec + M * vec.
void	sgstrs (trans_t trans, SuperMatrix *L, SuperMatrix *U, int *perm_c, int *perm_r, SuperMatrix *B, SuperLUStat_t *stat, int *info)
void	sprint_soln (int n, int nrhs, float *soln)

---

Detailed Description

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

 Purpose
 =======

 SGSTRS 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
 SGSTRF.

 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
         sgstrf(). Use compressed row subscripts storage for supernodes,
         i.e., L has types: Stype = SLU_SC, Dtype = SLU_S, Mtype = SLU_TRLU.

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

void slsolve	(	int	ldm,
		int	ncol,
		float *	M,
		float *	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 smatvec	(	int	ldm,
		int	nrow,
		int	ncol,
		float *	M,
		float *	vec,
		float *	Mxvec
	)

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

void sprint_soln	(	int	n,
		int	nrhs,
		float *	soln
	)

void susolve	(	int	ldm,
		int	ncol,
		float *	M,
		float *	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.