! ===========================================================================
! README
! ===========================================================================
! This program solves the wave equation in 1+1 dimensions.

!     Copyright (C) 2012  Edison Montoya, eamonto@gmail.com

!     This program is free software: you can redistribute it and/or modify
!     it under the terms of the GNU General Public License as published by
!     the Free Software Foundation, either version 3 of the License, or
!     (at your option) any later version.

!     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
!     GNU General Public License for more details.

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

! Up to date: 29 Feb 2012					


To compile the program execute in the terminal:

$make


To run the program execute:

$make run


All the outputs are written into the directory "outputfile" given in the 
parameters module (param.f90).


The files into this repository are:

! ===========================================================================
! main.f90
! ===========================================================================
! Principal program, this program solves the wave equation in 1+1 dimensions.


! ===========================================================================
! param.f90
! ===========================================================================
! Global parameters for the physical system.


! ===========================================================================
! initial_data.f90
! ===========================================================================
! Here are initialize all the functions defined on the grid.


! ===========================================================================
! boundaries.f90
! ===========================================================================
! Implementation of the boundaries conditions


! ===========================================================================
! sources.f90
! ===========================================================================
! Here are implemented the right hand side (derivatives) of the functions
! to be evolve in time.


! ===========================================================================
! mylibrary.f90
! ===========================================================================
! Library to evolve an arbitry physical system on a 1 dimensional grid using 
! a Runge-Kutta 4 method. Also includes memory allocation and output routines.

 The structures used in the library are:

  !Functions on the grid to be integrated
  type :: dynamical_func

  !Extra functions that are not evolve
  type :: extra_func


 The routines in the library are:

  !Implemetation of the Runge-Kutta 4 method 
  subroutine evolution_rk4(k,func,time_step)

  !Store the initial values before the integration
  subroutine store_levels_rk4(func)

  !Allocation of function that are evolve
  subroutine allocate_dyn(func,grid_points)

  !Allocation of the function that are not evolve
  subroutine allocate_extra(func,grid_points)

  !Deallocation of function that are evolve
  subroutine deallocate_dyn(func)

  !Allocation of function that are not evolve
  subroutine deallocate_extra(func)

  !Created the output file for the dynamical functions "func" in  
  !the "output_dir" with name "output_file" and id "file_number"
  subroutine create_output(func,output_dir,output_file,file_number)

  !Print the output of two scalar functions on the grid
  subroutine output_obs_obs(axis1,axis2,output_file,file_number,Nx)