CscIlu CscIlu0 CscIluSolve CscSsorSolve CsrIlu CsrIlu0 CsrIluSolve CsrSsorSolve CsxDs CsxDsSolve CsxSsor

CsxSsor() Sub CsxSsor ( N As  Long, Omega As  Double, Val() As  Double, Ptr() As  Long, Ind() As  Long, D() As  Double, Optional Info As  Long, Optional Base As  Long = -1  ) Initialize symmetric successive over-relaxation (SSOR) preconditioner (CSC/CSR) Purpose This routine initializes the symmetric successive over-relaxation (SSOR) preconditioner for the coefficient matrix A of the sparse linear equations. The preconditioner matrix is defined as follows. M(ω) = (1/(2 - ω))(D/ω + L)(D/ω)^(-1)(D/ω + U) where L, D and U are the lower triangular part, the diagonal part and the upper triangular part of the coefficient matrix A, respectively (If A is a symmetric matrix, U = L^T). The output D() is used by CscSsorSolve(), CsrSsorSolve(), SscSsorSolve() or SsrSsorSolve(). Parameters [in] N Dimension of the matrix A. (N >= 0) (if N = 0, returns without computation) [in] Omega The relaxation parameter ω. (0 < ω < 2) [in] Val() Array Val(LVal - 1) (LVal >= nnz) Values of nonzero elements of matrix A. (nnz is number of non-zero elements) [in] Ptr() Array Ptr(LPtr - 1) (LPtr >= N + 1) Column pointers (CSC) / row pointers (CSR) of matrix A. [in] Ind() Array Ind(LInd - 1) (LInd >= Nnz) (Nnz is number of nonzero elements of matrix A) Row indices (CSC) / column indices (CSR) of matrix A. [out] D() Array D(LD - 1) (LD >= N) Diagonal elements of preconditioner matrix M. [out] Info (Optional) = 0: Successful exit. = i < 0: The (-i)-th argument is invalid. = j > 0: j diagonal elements are zero (Returns 1/ω in D() for such elements). [in] Base (Optional) Indexing of Ptr() and Ind(). = 0: Zero-based (C style) indexing: Starting index is 0. = 1: One-based (Fortran style) indexing: Starting index is 1. (default: Assumes 1 if Ptr(0) = 1, 0 otherwise) Example Program See examples of CsrSsorSolve and CscSsorSolve.