This directory contains  the PSBLAS library, version 3.5.


 
The architecture of the Fortran 2003 sparse BLAS is described in 
S. Filippone, A. Buttari:
Object-Oriented Techniques for Sparse Matrix Computations in Fortran
2003, 
ACM Trans. on Math. Software, vol. 38, No. 4, 2012.

The ideas are explored further with the paper:

V. Cardellini, S. Filippone and D. Rouson
Design Patterns for  sparse-matrix computations on
hybrid CPU/GPU platforms, 
Scientific Programming, 22(2014), pp.1-19.


Version 1.0 of the library was described in:
S. Filippone, M. Colajanni
PSBLAS: A library for parallel linear algebra computation on sparse matrices
ACM Trans. on Math. Software, 26(4), Dec. 2000, pp. 527-550.


UTILITIES
The test/util directory contains some utilities to convert to/from
Harwell-Boeing and MatrixMarket file formats. 


DOCUMENTATION

See docs/psblas-3.5.pdf; an HTML version of the same document is
available in docs/html. 
Please consult the sample programs, especially 
test/pargen/psb_[sd]_pde[23]d.f90



OTHER SOFTWARE CREDITS 

We originally included a modified implementation of some of the
Sparker (serial sparse BLAS)  material; this has been completely
rewritten, way beyond the intention(s) and responsibilities of the
original developers. 
The main reference for the serial sparse BLAS is: 
Duff, I., Marrone, M., Radicati, G., and Vittoli, C.
Level 3 basic linear algebra subprograms for sparse matrices: a user 
level interface
ACM Trans. Math. Softw., 23(3), 379-401, 1997.


INSTALLING

To compile and run our software you will need the following
prerequisites (see also SERIAL below):

1. A working version of MPI

2. A version of the BLAS; if you don't have a specific version for
   your platform you may try ATLAS available from
   http://math-atlas.sourceforge.net/ 

3. We have had good results with  the METIS library, from 
   http://www-users.cs.umn.edu/~karypis/metis/metis/main.html 
   This is optional; it is  used in the util and test/fileread
   directories but only if you specify --with-metis.

4. If you have the AMD package of Davis, Duff and Amestoy, you can
   specify  --with-amd (see ./configure --help for more details). 

The configure script will generate a Make.inc file suitable for
building the library.  
The script is capable of recognizing the needed libraries with their
default names; if they are in unusual places consider adding the paths
with --with-libs, or explicitly specifying the names in --with-blas, etc. 
Please note that a common way for the configure script to fail is to
specify inconsistent MPI vs. plain compilers, either directly or
indirectly via environment variables; e.g. specifying the Intel
compiler with FC=ifort while at the same time having an  MPIFC=mpif90
which points to GNU Fortran. 
The best way to avoid this situation is (in our opinion) to use the
environment modules package (see http://modules.sourceforge.net/), and
load the relevant variables with (e.g.)  
module load gnu46 openmpi
This will delegate to the modules setup to make sure that the version
of openmpi in use is the one compiled with the gnu46 compilers. 
After the configure script has completed you can always tweak the
Make.inc  file yourself. 

After you have Make.inc fixed,  run 
 make 
to  compile the library; go to the test directory and its
subdirectories to get test programs done.   
If you specify --prefix=/path you can do make install and the
libraries will be installed under /path/lib, while the module files
will be installed under /path/include.

SERIAL

Configuring with --enable-serial will provide a fake MPI stub library
that enables running in pure serial mode; no MPI installation is
needed in this case (but note that the fake MPI stubs are only
guaranteed to cover what we use internally, it's not a complete
replacement). 

LONG INTEGERS

We have an experimental flag --enable-long-integers that will enable having
8-byte integer data, allowing an index space larger than 2G; some
small cases have been tested but we do not offer full guarantee (yet). 



TODO:
Fix all reamining bugs. Bugs? We dont' have any ! ;-)


The PSBLAS team. 

RELATED SOFTWARE


If you are looking for more sophisticated preconditioners, you may be
interested in the package  MLD2P4 from http://github.com/sfilippone/mld2p4-2


Contact: https://github.com/sfilippone/psblas3
