# FreeBSD Manual Pages

```BSpar_gmres(3)			 BlockSolve95			BSpar_gmres(3)

NAME
BSpar_gmres - Solve a nonsymmetric system of equations using gmres pre-
conditioned by one of several preconditioners.  The rhs can be a	 block
of vectors.

INPUT PARAMETERS
BS     -	the number of vectors in the RHS
A      -	a sparse matrix
fact_A -	the incomplete factored	version	of A, if any
comm_A -	the communication structure for	A
in_rhs -	the contiguous block of	vectors	forming	the rhs
pre_option
-	the preconditioner to use PRE_ICC: incomplete Cholesky factor-
ization PRE_ILU: incomplete LU factorization  PRE_SSOR:  Succes-
sive over	relaxation PRE_BJACOBI:	Block Jacobi
err_tol
-	 the tolerance to which	to solve the problem stop if the esti-
mated norm of the	residual divided by the	norm  of  the  rhs  is
less than	err_tol
max_iter
-	the maximum number of iterations to take
residual
-	the final computed residual
guess  -	if TRUE, then initialize out_x to 0, otherwise the program as-
sumes that out_x contains	an initial guess
procinfo
-	the usual processor stuff

OUTPUT PARAMETERS
out_x  -	the contiguous block of	vectors	containing the solution

RETURNS
The number of iterations	or a negative number indicating	the number  of
iterations  prior to finding that the matrix (or	preconditioner)	is not
positive	definite.

NOTES
The preconditioners must	be computed  prior  to	calling	 BSpar_isolve.
For more	information on the preconditioners, see	the manual.

SYNOPSIS
int BSpar_gmres(int BS, BSpar_mat *A, BSpar_mat *fact_A,	BScomm *comm_A,
FLOAT *in_rhs, FLOAT *out_x, int pre_option, int restart, FLOAT	err_tol,
int max_iter, FLOAT *residual, int guess, BSprocinfo *procinfo)

LOCATION
BlockSolve95/src/BSpar_gmres.c

12/25/1995			BSpar_gmres(3)
```

NAME | INPUT PARAMETERS | OUTPUT PARAMETERS | RETURNS | NOTES | SYNOPSIS | LOCATION

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