dcreate_ilu_genr 

Generate incomplete LU preconditioner for general storage by rows

FORMAT

   DCREATE_ILU_GENR (a, ia, ja, nz, plu, n)

Arguments

  a                   real*8
                      On entry, a one-dimensional array of length at least 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
                      n+1,  containing the starting indices of each row in
                      arrays JA and A.
                      On exit, ia is unchanged.

  ja                  integer*4
                      On entry, a one-dimensional array of length at least
                      nz, containing the column values of each nonzero
                      element of the  matrix A.
                      On exit, ja is unchanged.

  nz                  integer*4
                      On entry, the number of nonzero elements in array A.
                      On exit, nz is unchanged.

  plu                 real*8
                      On entry, a one-dimensional array of length at least
                      nz.
                      On exit, array PLU contains information used by the
                      Incomplete LU preconditioner.

  n                   integer*4
                      On entry, the order of the matrix A.
                      On exit, n is unchanged.

Description

  DCREATE_ILU_GENR computes the information required by the Incomplete LU
  preconditioner for a sparse matrix stored using the general storage by rows
  scheme. The array PLU contains the real information for use by the
  preconditioner. The integer information is identical to the information in
  arrays IA and JA and is therefore not generated.

  The routine DCREATE_ILU_GENR is called prior to a call to one of the
  iterative solver routines with Incomplete LU preconditioning.