NAME

BSpar_solve - General solver of a system of equations preconditioned by one of several preconditioners and using one of several possible methods. The rhs can be a block of vectors.

INPUT PARAMETERS

A

- a sparse matrix

fact_A

- the incomplete factored version of A, if any

comm_A

- the communication structure for A

rhs

- the contiguous block of vectors forming the rhs

residual

- the final computed residual

OUTPUT PARAMETERS

x

- the contiguous block of vectors containing the solution (can contain an initial guess if BSctx_set_guess() is set.

NOW SPECIFIED IN PROCINFO CONTEXT

pre_option

- the preconditioner to use:
PRE_ICC: incomplete Cholesky factorization
PRE_ILU: incomplete LU factorization
PRE_SSOR: Successive over relaxation
PRE_BJACOBI: Block Jacobi

err_tol

- the tolerance to which to solve the problem stop if the estimated 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

guess

- if TRUE, then initialize out_x to 0, otherwise the program assumes that out_x contains an initial guess

procinfo

- the usual processor stuff

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_solve. For more information on the preconditioners, see the manual or BSctx_set_pre().

SYNOPSIS

int BSpar_solve(BSpar_mat *A, BSpar_mat *fact_A, BScomm *comm_A,


 FLOAT *rhs, FLOAT *x, FLOAT *residual, BSprocinfo *procinfo)

LOCATION

BlockSolve95/src/BSpar_solve.c