/* 
   
   Copyright (C) Bernard Piette 
                 University of Durham (UK) 
                 Department of Mathematical Sciences
   
   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 2 of the License, or
   (at your option) any later version.
   
   You can modify or use any part of the source code but only under the  
   condition that this Copyright notice is kept in the resulting source file.
*/
#include <pde.h>
#include <grf_pde.h>
#include <iostream>

using namespace std;


// Constructor
// Get the parameters from the pde
// file_name the name for the output file
//****************************************
grf_pde::grf_pde(pde *pde,string file_name) : file_name_(file_name)
{ nx_    = pde->nx();
  xmin_  = pde->xmin();
  xmax_  = pde->xmax();
  dx_    = pde->dx();
};

// Ouput a single txt 1D graphic file                        
// findex : file index                                       
// p : pointer to the data array                              
// t : value of t for the snapshot                            
// Output format:                                             
// The file should be a .m file. It can be execute by matlab 
//    # t = t                                                
//    ti Fi                                                  
// The file can be plotted using the following gnuplot command:
//    gnuplot> plot 'FILENAME' with lines
// Throw a string on error                                    
//***************************************************************
void grf_pde::write_1_grf(int findex,double *p, double t)
{ int ix,index;
  double x;
  string fname = make_file_name(file_name_,findex,"txt");

  ofstream ofs(fname.c_str());

  if(!ofs)
  { throw((string)" Error: Can't open file : "+fname);
  }

  ofs <<"# t = "<<t<<";\n";
  index = 0 ;
  x = xmin_;
  for(ix = 0; ix < nx_; ix += 1)
  { ofs << x << " " << p[index] << "\n";
    ++index;
    x += dx_;
  }
}

// Create a file name of the form:
//    NAME_DDD.XXX
// where NAME is the string name
//       DDD is the index
//       XXX is the suffix
// Return the nameas a string   
//*******************************
string grf_pde::make_file_name(string name,int index,string suffix)
{ char Buff[40];

  sprintf(Buff,"%d",index);

  return(name+"_"+Buff+"."+suffix);
}