release_2.1-notes.txt

来自「并行解法器,功能强大」· 文本 代码 · 共 82 行

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In addition to bug fixes, Aztec 2.1 has the following new features:

1) MPI communicators can now be used with Aztec.
2) Matrix-free interface is much improved.
   a) easier to provide matrices and preconditioners
   b) an experimental getrow capability allows matrix-free codes
      use Aztec preconditioners.
3) A matrix-capture facility for exporting matrices to programs
   like matlab.
4) total solution time now appears in AZ_status
5) There are a number of experimental features that are not
   officially released (and so not discussed in the manual)
   such as solving complex arithmetic matrices, using pivoting 
   within the bilu scheme, and using Aztec with multi-level preconditioners. 
   Those interested in these should contact us.

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In order for Aztec 2.0 users to be compatible with Aztec2.1, several
changes need to be made.

   1) The only real makefile change is that MPI_LIB_DIR has been
      replaced by MPI_LIB in which the mpi library must be given
      (see the install README). 

   2) Calls to AZ_matvec_mult() should be replaced by either 
         AZ_MSR_matvec_mult() or AZ_VBR_matvec_mult() 

   3) Calls to AZ_exchange_bdry(x, data_org) need to append proc_config to parameters:
      AZ_exchange_bdry(x, data_org, proc_config)

   4) Calls to AZ_processor_info(proc_config) should be replaced by 
      AZ_set_proc_config():

         MPI USERS    ==> AZ_set_proc_config( proc_config, MPI_COMM_WORLD); 
         nonMPI USERS ==> AZ_set_proc_config( proc_config, AZ_NO_MPI); 

   5) For AZ_iterate() users, matrices have changed (see user's manual).  In particular,

      a) The structure AZ_MATRIX should not be declared. Instead an AZ_MATRIX
         pointer is declared followed by 
            Amat = AZ_matrix_create(N_equations);
         where N_equations is the number of local matrix rows on this processor 

      b) Fields in AZ_MATRIX should be set via 

            AZ_set_MSR(Amat, bindx, val, data_org, 0, NULL, AZ_LOCAL),
            AZ_set_VBR(Amat, rpntr, cpntr, bpntr, indx, bindx,
                       val, data_org, 0, NULL, AZ_LOCAL),
         or
            AZ_set_MATFREE(Amat, &pass_data, example_specific_matvec);

         where  '0, NULL, AZ_LOCAL' currently are not used but will allow 
                for globally numbered matrices in the future, 
                'example_specific_matvec' is a user defined matvec function 
         and    'pass_data' is a user defined void* data pointer passed back to 
                the users 'matvec'.

      c) AZ_matrix_destroy(&Amat) should be used for freeing.

         NOTE: Does not free arrays passed in via set functions: bindx, val, 
         data_org, rpntr, cpntr, bpntr, indx. 

      d) AZ_create_matrix(), AZ_create_commless_matrix(), AZ_delete_matrix(), and 
         AZ_delete_commless_matrix() should no longer be used.

   6) Preconditioners within the AZ_iterate() interface have changed. In particular,

      a) The structure AZ_PRECOND should not be declared. Instead an AZ_PRECOND 
         pointer is declared followed by 

            Prec = AZ_precond_create(Pmat, precond_function, precond_data);

         where Pmat is an AZ_MATRIX*, precond_function is either AZ_precondition 
         (to use Aztec preconditioners) or a user-defined preconditioning function, 
         and precond_data is a data pointer for use with a user's preconditioner.

      b) AZ_precond_destroy(&Prec) should be used for freeing.

         NOTE: Does not free Pmat or precond_data.