# FreeBSD Manual Pages

```BSpar_sym_solve(3)		 BlockSolve95		    BSpar_sym_solve(3)

NAME
BSpar_sym_solve	-  Solve a symmetric positive definite system of equa-
tions using conjugate gradients preconditioned by one of	 several  pre-
conditioners.   The rhs can be a	block of vectors.  The user should not
call this function directly, but	BSpar_solve().

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

LOCATION
BlockSolve95/src/BSpar_sym_solve.c

2/12/1996		    BSpar_sym_solve(3)
```

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

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