DCREATE_POLY_SDIA (a, ia, ndim, nz, p, n)
a real*8 On entry, a two-dimensional array with dimensions ndim by nz containing the nonzero elements of the matrix A. On exit, a is unchanged. ia integer*4 On entry, a one-dimensional array of length at least nz, containing the distances of the diagonals from the main diagonal. On exit, ia is unchanged. ndim integer*4 On entry, the leading dimension of array A, as declared in the calling subprogram; ndim >= n. On exit, ndim is unchanged. nz integer*4 On entry, the number of diagonals stored in array A. On exit, nz is unchanged. p real*8 On entry, a one-dimensional array of length at least 3*n. On exit, array P contains information for use by the polynomial preconditioner. n integer*4 On entry, the order of the matrix A. On exit, n is unchanged.
DCREATE_POLY_SDIA computes the information required by the polynomial preconditioner for a sparse matrix stored using the symmetric diagonal storage scheme. The real part of this information is returned in the array P. There is no integer information returned for this preconditioner. Part of the array P is used as workspace during the application of the preconditioner. The routine DCREATE_POLY_SDIA is called prior to a call to one of the iterative solver routines with polynomial preconditioning. This routine is available in both serial and parallel versions. The routine names and parameter list are identical for both versions. For information about linking to the serial or to the parallel library, refer to the CXML Reference Manual.
Index of CXML Routines