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@ -1,23 +1,56 @@
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This directory contains the MLD2P4 set of preconditioners, version 2.1
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MLD2P4 version 2.1
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MultiLevel Domain Decomposition Parallel Preconditioners Package
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based on PSBLAS (Parallel Sparse BLAS version 3.5)
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Salvatore Filippone Cranfield University, UK
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Pasqua D'Ambra IAC-CNR, Naples, IT
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Daniela di Serafino Univ. of Campania "L. Vanvitelli", Caserta, IT
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---------------------------------------------------------------------
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MLD2P4 (Multi-Level Domain Decomposition Parallel Preconditioners
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Package based on PSBLAS (MLD2P4) provides parallel Algebraic MultiGrid
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(AMG) and Domain Decomposition preconditioners, to be used in the
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iterative solution of linear systems.
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The name of the package comes from its original implementation,
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containing multi-level additive and hybrid Schwarz preconditioners,
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as well as one-level additive Schwarz preconditioners. The current
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version extends the original plan by including multi-level cycles
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and smoothers widely used in multigrid methods. A purely algebraic
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approach is applied to generate coarse-level corrections, so that
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no geometric background is needed concerning the matrix to be
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preconditioned. The matrix is assumed to be square, real or complex.
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MLD2P4 has been designed to provide scalable and easy-to-use
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preconditioners in the context of the PSBLAS (Parallel Sparse Basic
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Linear Algebra Subprograms) computational framework and is used
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in conjuction with the Krylov solvers available from PSBLAS. The
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package employs object-oriented design techniques in Fortran 2003,
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with interfaces to additional third party libraries such as MUMPS,
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UMFPACK, SuperLU, and SuperLU_Dist, which can be exploited in building
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multilevel preconditioners. The parallel implementation is based on
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a Single Program Multiple Data (SPMD) paradigm; the inter-process
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communication is based on MPI and is managed mainly through PSBLAS.
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WHAT'S NEW
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Version 2.1
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1. The multigrid preconditioner now include fully general V- and W-
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cycles. We also support K-cycles, both for symmetric and
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1. The multigrid preconditioner now include fully general V- and
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W-cycles. We also support K-cycles, both for symmetric and
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nonsymmetric matrices, intended to be used in conjunction
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with Flexible CG or GCR available in PSBLAS 3.5.
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2. The smoothers now include popular
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variants such as Jacobi, forward and backward hybrid
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Gauss-Seidel (intra-process Gauss-Seidel, inter-process
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block-Jacobi).
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3. The PRE and POST specification for smoothers can now be
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2. The smoothers now include popular variants such as Jacobi,
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forward and backward hybrid Gauss-Seidel (intra-process
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Gauss-Seidel, inter-process block-Jacobi).
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3. The PRE and POST specification for smoothers can now be
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specified independently of each other: you can even specify
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different smoothers for PRE and POST (e.g. forward Gauss-Seidel
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PRE with backward Gauss-Seidel POST). The default is to
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have the specs apply to both PRE and POST.
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Version 2.0.
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Finally moved to F2003, with the support of PSBLAS3.
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Daniela di Serafino
7 years ago