WHAT'S NEW

AMG4PSBLAS
Version 1.2
   1. New polynomial smoothers.
   2. Introduced L1-variants
   3. Reorganization of sample programs.
   
Version 1.1
   1. Reworked approximate inverse solvers.
   

Version 1.0
   1. Transitioned from MLD2P4

MLD2P4
Version 2.1
   1. The multigrid preconditioner now include fully general V- and
      W-cycles. We also support K-cycles, both for symmetric and 
      nonsymmetric matrices, intended to be used in conjunction 
      with Flexible CG or GCR available in PSBLAS 3.5.
   2. The smoothers now include popular variants such as Jacobi,
      forward and backward hybrid Gauss-Seidel (intra-process
      Gauss-Seidel, inter-process block-Jacobi).
   3. The PRE and POST specification for smoothers can now be 
      specified independently of each other: you can even specify
      different  smoothers for PRE and POST (e.g. forward Gauss-Seidel
      PRE with backward Gauss-Seidel POST). The default is to
      have the specs apply to both PRE and POST. 

Version 2.0.
   Finally moved to F2003, with the support of PSBLAS3.
   There are a few minor differences at user level: 
   1. In the configure step, you should specify the INSTALL directory
      of PSBLAS version 3.4, not the source directory;
   2. In the various makefiles, libmld_prec.a should now be used in
      addition (and in front of) libpsb_prec.a, and no longer in
      place of it.
   3. As for the basic usage, this is practically identical to the
      previous version(s).  
   
   You should use the same MPI/serial compilers that were used for the
   PSBLAS installation. 
   The Fortran 2003 support means that it is far easier to develop and
   integrate new solvers and smoothers; you need to take one of the
   existing solvers/smoothers as a model, develop your own by
   changing/replacing the model contents, and then pass the new object
   to the PREC%SET() method which will copy into the internals, as per
   the PROTOTYPE design pattern. Take a look at the test/newslv
   directory to see an example. It's easier done than said!

   Versions of third party libraries known to work: 
   UMFPACK:      4.5.4  of SuiteSparse
   MUMPS:        4.10.0 and 5.0.1
   SuperLU:      4.3    and 5.0
   SuperLU_Dist: 3.3    and 4.2
   Note that with SuperLU_Dist you will probably need to add further
   link options, e.g. the ParMetis library or the openmp runtime;
   you can do this using the configure option --with-extra-libs

In version 1.1:
-  The MLD_SIZEOF() function has been redefined to be INTEGER(8), so
   as to be able to measure large data sets.
-  The internals of the multilevel preconditioner have been repackaged
   in a more structured fashion; no changes are needed in the user
   code.
-  Note that we now need version 2.3.1 of PSBLAS.
   


Contributors
Salvatore  Filippone 
Pasqua     D'Ambra
Daniela    di Serafino
Ambra	   Abdullahi Hassan
Alfredo    Buttari
