PPM numerics package README
===========================
v1.2.2, May 2016


Introduction
------------

This is the PPM numerics source package.

Changes
-------

.1.2.2
************************************************************************
This version is the first (and last) release of PPM numerics based on the
conventional PPM core data structures. (The next release will be using the PPM
core abstractions)

.New Features
- Using the PPM core build system
- Added FFTW3 wrappers for the Poisson solver

.Fixes
- Fixed the Multigrid solver
- Added Fortran 2003 style ODE RHS function interfaces
- Various fixes in the build system.
************************************************************************


Requirements for building PPM numerics
--------------------------------------

- PPM core 1.2.2: This PPM numerics version is based on PPM core 1.2.2 and can
  only be linked against this version. Please first download and compile PPM
  core 1.2.2 before attempting to compiling this package.
- FFTW 3: The Poisson solver module requires FFTW3 to be present and installed.
  The library should be built with the same compiler as PPM numerics to ensure
  binary compatibility.
- An MPI distribution (optional): Either get OpenMPI, mpich2 or any other MPI 2
  compliant MPI library. If you are compiling PPM on a cluster, most likely your
  sysadmin will have already an MPI installed on the system.

Make sure that all requirements are compiled with the same compiler that you
will be using to build PPM core.


Building PPM numerics
---------------------

PPM numerics is built in 3 simple steps:

Step 1: Configuring PPM numerics
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Run the `configure` script to allow the build system to determine the correct
options to compile PPM core.

It is very important to give `configure` the correct settings to make sure PPM
core is compiled correctly. To find out which settings are supported type

~~~~~~~~~~
$ ./configure --help
~~~~~~~~~~

This is what will be returned:

~~~~~~~~~~~~~~~~~~~~~~~~~~~
`configure' configures PPM 1.2.1 to adapt to many kinds of systems.

Usage: ./configure [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.

Configuration:
  -h, --help              display this help and exit
      --help=short        display options specific to this package
      --help=recursive    display the short help of all the included packages
  -V, --version           display version information and exit
  -q, --quiet, --silent   do not print `checking ...' messages
      --cache-file=FILE   cache test results in FILE [disabled]
  -C, --config-cache      alias for `--cache-file=config.cache'
  -n, --no-create         do not create output files
      --srcdir=DIR        find the sources in DIR [configure dir or `..']

Installation directories:
  --prefix=PREFIX         install architecture-independent files in PREFIX
                          [/usr/local]
  --exec-prefix=EPREFIX   install architecture-dependent files in EPREFIX
                          [PREFIX]

By default, `make install' will install all the files in
`/usr/local/bin', `/usr/local/lib' etc.  You can specify
an installation prefix other than `/usr/local' using `--prefix',
for instance `--prefix=$HOME'.

For better control, use the options below.

Fine tuning of the installation directories:
  --bindir=DIR            user executables [EPREFIX/bin]
  --sbindir=DIR           system admin executables [EPREFIX/sbin]
  --libexecdir=DIR        program executables [EPREFIX/libexec]
  --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
  --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
  --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
  --libdir=DIR            object code libraries [EPREFIX/lib]
  --includedir=DIR        C header files [PREFIX/include]
  --oldincludedir=DIR     C header files for non-gcc [/usr/include]
  --datarootdir=DIR       read-only arch.-independent data root [PREFIX/share]
  --datadir=DIR           read-only architecture-independent data [DATAROOTDIR]
  --infodir=DIR           info documentation [DATAROOTDIR/info]
  --localedir=DIR         locale-dependent data [DATAROOTDIR/locale]
  --mandir=DIR            man documentation [DATAROOTDIR/man]
  --docdir=DIR            documentation root [DATAROOTDIR/doc/ppm]
  --htmldir=DIR           html documentation [DOCDIR]
  --dvidir=DIR            dvi documentation [DOCDIR]
  --pdfdir=DIR            pdf documentation [DOCDIR]
  --psdir=DIR             ps documentation [DOCDIR]

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
  --enable-mpi[=impl.]    use MPI (default is no), If the MPI implementation
                          of your choice provides compile wrappers that are in
                          PATH, I can set them myself, choose: guess (I will
                          choose the first implementation I can find),
                          openmpi, lammpi, mpich, mpich2, intelmpi_gnu
                          (Intel's MPI with GNU Compilers), intelmpi_intel
                          (Intel's MPI with Intel Compilers), sun (Sun MPI),
                          ibm (IBM AIX POE). Else, set this flag with no value
                          and set CC, CXX and FC to the appropriate compiler
                          wrappers (safest)
  --enable-linux          compile for linux (default is no)
  --enable-etime          use etime (default is no)
  --enable-vector         enable __VECTOR (default is no)
  --enable-mathkeisan     enable __MATHKEISAN (default is no)
  --enable-sxf90          enable __SXF90 (default is no)
  --enable-crayfishpack   enable __CRAYFISHPACK (default is no)
  --enable-hypre          enable __HYPRE (default is no)
  --enable-no-microinstr  enable __NOMICROINSTRUCTIONS (default is no)
  --enable-dev            enable development mode (default is no)
  --enable-debug          enable debug mode (default is no)

Optional Packages:
  --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
  --with-ppm=path         set the path to the ppm core library - THIS FLAG
                          IS MANDATORY

Some influential environment variables:
  CXX         C++ compiler command
  CXXFLAGS    C++ compiler flags
  LDFLAGS     linker flags, e.g. -L<lib dir> if you have libraries in a
              nonstandard directory <lib dir>
  LIBS        libraries to pass to the linker, e.g. -l<library>
  CPPFLAGS    (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
              you have headers in a nonstandard directory <include dir>
  CC          C compiler command
  CFLAGS      C compiler flags
  CPP         C preprocessor
  FC          Fortran compiler command
  FCFLAGS     Fortran compiler flags

Use these variables to override the choices made by `configure' or to help
it to find libraries and programs with nonstandard names/locations.

Report bugs to the package provider.
~~~~~~~~~~~~~~~~~~~~~~~~~~~

Following options are especially important:

- `--with-ppm`: You must specify the PPM core path. This is either the path
  where ppm core was installed, or if you simply compiled ppm core, then you
  must point to the base path of ppm core (where the include and lib directories
  are located).
- `--enable-mpi`: If you will be running PPM clients on a parallel environment
  (a cluster) using MPI, you must specify which MPI implementation you are
  using. If your system is properly configured then this should be enough
  information for PPM core build system to find the MPI libraries and compiler
  wrappers needed. If this goes wrong, you may ommit this option and set
  compiler wrapper and libraries in `FC` and `LDFLAGS` respectively.
- `--enable-linux`: Set this if you're compiling/running on a Linux system
- `--prefix`: If you like to install PPM and the target directory is not the
  system's standard directory (`/usr/`) then you have to define this directory
  here. You must provide the full path. It is not necessary to install PPM.
  Building it and leaving it in the compilation directory is sufficient. If you
  provide a directory here it must already exist - it will not be created by the
  build system.
- `FC` etc.: If you wish to not use MPI or you have to specify exactly which
  compiler executable should be used, then you can use this flag to set your
  compiler.
- `LDFLAGS`: If metis was not installed in one of the system's standard library
  directories (e.g. `/usr/lib`) you must specify the directory to the libmetis.a
  file here.

Here two examples on how you could run the configure command

`.configure` on Linux cluster using OpenMPI (and intel compilers, wrapped)
~~~~~~~~~~~~~~~~~~~~~~~~~~~
$ ./configure --with-ppm=../../ppmcore --enable-mpi=openmpi LDFLAGS=-L../../metis/lib --enable-linux
~~~~~~~~~~~~~~~~~~~~~~~~~~~

`./configure` on Mac OS X workstation with the MacPorts gcc compilers
~~~~~~~~~~~~~~~~~~~~~~~~~~~
$ ./configure --with-ppm=../../ppmcore FC=gfortran-mp-4.4 LDFLAGS=-L../../metis/gcc/lib 
~~~~~~~~~~~~~~~~~~~~~~~~~~~

`./configure` on a computer with OpenMPI installed in a non-standard location

~~~~~~~~~~~~~~~~~~~~~~~~~~~
./configure --with-ppm=../../ppmcore --enable-mpi=openmpi FC=/opt/openmpi/1.5/bin/mpif90 \
            LDFLAGS=-L../../metis/gcc/lib
~~~~~~~~~~~~~~~~~~~~~~~~~~~


Step 2: Compiling PPM numerics
~~~~~~~~~~~~~~~~~~~~~~~~~~

If the configure process finished successfully you should see on your screen a
message that the Makefile has been generated (and you can now find this
Makefile in this directory).

Now you can simply run make to compile PPM core:

~~~~~~~~~~~~~~~~~~~~~~~~~~~
$ make
~~~~~~~~~~~~~~~~~~~~~~~~~~~

If you encounter problems in the compilation process (compile errors) please,
first check if you have set everything correctly in your environment. If the
error persists, please send us a bug-report detailing the previous steps you
have performed. Also, please include the `config.log` file and the output of
`export`. Finally, if yu are using MPI, please include which MPI library you are
using.


Step 3: Installing PPM numerics (optional)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If you wish to install PPM core you can now use the `make install` command to do
so:

~~~~~~~~~~~~~~~~~~~~~~~~~~~
$ make install
~~~~~~~~~~~~~~~~~~~~~~~~~~~

If the target directory is part of the system, you will most probably get a
message that you have insufficient rights. If you have a root account you can
use in this case the sudo command to override this security setting.

~~~~~~~~~~~~~~~~~~~~~~~~~~~
$ sudo make install
~~~~~~~~~~~~~~~~~~~~~~~~~~~

Your PPM core distribution is installed.

Compiling PPM client code against PPM numerics
----------------------------------------------
When compiling your PPM client code you need to first include the PPM core modules: 

- in `include/` relative to this directory. Check which compiler flag needs to
  be used to include Fortran module directories.

and link against libppm.a:

- in `lib/` relative to this directory. Add -L[path to lib] -lppmnumerics to the
  linking command of your compilation process.


Enjoy the PPM experience!


Contributors
------------

The PPM library is being maintained and developed by the CSE-lab (group of
Professor Petros Koumoutsakos), the MOSAIC group at MPI-CBG Dresden (group
of Prfessor Ivo F.Sbalzarini) and the Center for Fluid Dynamics at DTU (group 
of Professor Jens Walther).

PPM core package maintainer: Yaser Afshar <afshar@mpi-cbg.de>