NAG Fortran Library Routine Document F11DSF

This routine solves a complex sparse non-Hermitian system of linear equations: Ax 1⁄4 b; using an RGMRES (Saad and Schultz (1986)), CGS (Sonneveld (1989)), Bi-CGSTAB(‘) (Van der Vorst (1989), Sleijpen and Fokkema (1993)), or TFQMR (Freund and Nachtigal (1991), Freund (1993)) method. F11DSF allows the following choices for the preconditioner: no preconditioning; Jacobi preconditioning (Young (1971)); symmetric successive-over-relaxation (SSOR) preconditioning (Young (1971)). For incomplete LU (ILU) preconditioning see F11DQF. The matrix A is represented in coordinate storage (CS) format (see Section 2.1.1 of the F11 Chapter Introduction) in the arrays A, IROW and ICOL. The array A holds the non-zero entries in the matrix, while IROW and ICOL hold the corresponding row and column indices. F11DSF is a black-box routine which calls F11BRF, F11BSF and F11BTF. If you wish to use an alternative storage scheme, preconditioner, or termination criterion, or require additional diagnostic information, you should call these underlying routines directly.