This file includes instructions and information on how to build and
use the SAAMGE library.

1. License and Disclaimer Statements

SAAMGE: smoothed aggregation element based algebraic multigrid hierarchies
        and solvers.

Copyright (c) 2018, Lawrence Livermore National Security,
LLC. Developed under the auspices of the U.S. Department of Energy by
Lawrence Livermore National Laboratory under Contract
No. DE-AC52-07NA27344. Written by Delyan Kalchev, Andrew T. Barker,
and Panayot S. Vassilevski. Released under LLNL-CODE-667453.

This file is part of SAAMGE. 

Please also read the full notice of copyright and license in the file
LICENSE.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License (as
published by the Free Software Foundation) version 2.1 dated February
1999.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
conditions of the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this program; if not, see
<http://www.gnu.org/licenses/>.

2. Requirements

The code almost entirely relies on standard language (C++)
features. Additionally, a few POSIX functions are used but only for
less important functionalities in the code. It is tested for:

GCC 4.4.7 20120313 (http://gcc.gnu.org/)
MFEM 3.1 (http://www.mfem.org)
GLVIS 3.0 (http://www.glvis.org)
METIS 5.0.2 (http://glaros.dtc.umn.edu/gkhome/views/metis)
HYPRE 2.10.0b (https://computation-rnd.llnl.gov/linear_solvers/)

The build system relies on UNIX-like properties of the environment. It
is not tested if it would work properly when emulated environments
like CYGWIN are used.

The compiler must be invoked with parameters enabling Run-Time Type
Information (RTTI). Usually this is enabled by default for GCC.

2. Libraries, Tools, and Header Files Needed

2.1 Libraries

When linking SAAMGE against executables, you will need to link against
all the libraries listed above, and in addition:

BLAS (http://www.netlib.org/blas/, see also http://math-atlas.sourceforge.net/)
LAPACK (http://www.netlib.org/lapack/)

Additionally, due to the use of FORTRAN, the libraries GFORTRAN
(http://gcc.gnu.org/fortran/) and/or G2C (http://www.kilmnj.com/g77/)
may be required depending on the FORTRAN compiler. Currently, GFORTRAN
is assumed and expected by default.

We use CMake (www.cmake.org) for configuring and building SAAMGE.

2.2 Tools

If visualization is desired, GLVIS has to be running. It requires MFEM
and also other libraries like GL, GLU, X11, PTHREAD, and possibly
others. That is, some modifications of the makefile and extra work
might be necessary depending on the circumstances. Once the executable
is available it only needs to be executed in some terminal to have
GLVIS up and running. Have in mind that GLVIS generates a lot of
output so even if it is executed in background (unless the standard
outputs are redirected) the terminal will still not be very usable.

3. Building

To configure and build, see the file 'BASE/amg/sample_config.sh'
which gives an example of how to use CMake to create GNU
makefiles. Then typing 'make' in the build directory shold
build the library, tests, and examples.

4. Output and Debug

In 'BASE/amg/inc/config.hpp' settings for the debug and
output levels can be found and modified as necessary.