#
#  PyMFEM extension sample
#

This example is written for parallel (MPI) version of PyMFEM.
You need to have python2.7 with mpi4py. 

#
# How to build this sample
#

1) prepare Makefile

edit Makefile. You need to set compiler (mpicxx), location of
include/lib of various libraries.

2) build

make extension   # build/install the sample external library
make cxx         # generate a wrapper code to wrap the sample library
make so          # compile a wrapper code
make install     # install


Alternatively, you can pass these parameters from arguments as follows 

 make <build command>  PREFIX=~/sandbox \
                       MFEM_LNK_DIR=~/sandbox/mfem-git/par/lib \
        	       MFEM_INC_DIR=~/sandbox/mfem-git/par/include \
	               CC=mpicc CXX=mpicxx \
                       HYPRE_INC_DIR=~/sandbox/include      \
                       METIS_INC_DIR=~/sandbox/include
		       
where <build command> is extension, cxx, so, and install		       

#
# How to use this sample
#
1) Build Files

This build process of sample extension is done by following files.

Makefile                  # Entry point of build process. Enviromental variables are set here
setup.py                  # python script to build python extension wrapper and install it
ext/CMakeLists.txt        # CMake file to build a sample library
mfem_ext_sample/Makefile  # called from top-level Makefile


#
# test result
#
Python 2.7.15 (default, May  2 2018, 00:53:27) 
Type "copyright", "credits" or "license" for more information.

IPython 5.4.0 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: import mfem_ext_sample.sample_a

In [2]: dir(mfem_ext_sample.sample_a)
Out[2]: 
['__builtin__',
 '__builtins__',
 '__doc__',
 '__file__',
 '__name__',
 '__package__',
 '_newclass',
 '_object',
 '_sample_a',
 '_swig_getattr',
 '_swig_property',
 '_swig_repr',
 '_swig_setattr',
 '_swig_setattr_nondynamic',
 'sample_PyMFEM_ext',
 'sample_PyMFEM_ext_swigregister']

In [3]: refiner = mfem_ext_sample.sample_a.sample_PyMFEM_ext()
Conctructor called

In [4]: refiner.get_refine()
Out[4]: 1

In [5]: import mfem.par
In [8]: mesh = mfem.par.Mesh('test.msh')

In [9]: mesh.GetNV()
Out[9]: 14

In [10]: refiner.call_refine(mesh)

In [11]: mesh.GetNV()
Out[11]: 63