#include <math.h>
#include <iostream>
#include <fstream>
#include "rk2.hh"
#include "rk4.hh"
#include "euler.hh"
#include "heun.hh"
#include "f.hh"
#include <iomanip>

using namespace  std;

int main()
{
  double a=0.0;
 
  double h=0.2;
  double y0=1.0;
  //  int N = 10;
  double b= 1.0;
  int N = (int) (b-a)/h +1;
  
  double heunout[N];
  double eulerout[N];

  double rk2out[N];
  double rk4out[N];

  

  
  euler(a,b,h,N,y0,eulerout);
  heun(a,b,h,N,y0, heunout);
  rk2(a,b,h,N,y0,rk2out);
  rk4(a,b,h,N,y0,rk4out);
  
//scrivi i risultati

  
  ofstream os;
  os.open("out.dat");
  if(not os) cout <<"unable to oper/write file'out.dat', " << endl;
  else
    {
      os<<setw(15) <<"passo" << setw(15) << "X" << setw(15) << "Y-SolAnalit."<< setw(15) <<"Y-Eulero"<< setw(15) <<"Y-Heun"<< setw(15)<<"Y-RK2"<< setw(15) <<"Y-RK4"<< setw(15) << endl;
      for (int i=0; i<N; i++)
	{
         //yT  //soluzione analitica  Y(x) = x-1+2exp(-x);
          double e=2.71828;
          double yT = a -1 +2.0*pow(e,-a);
          
    	  os << i << setw(15) << setprecision (6) << fixed << a << setw(15) << setprecision (6) <<fixed << yT<< setw(15) << setprecision (6) << fixed << eulerout[i] << setw(15) << setprecision (6) << fixed<< heunout[i]<< setw(15) << setprecision (6)<< fixed  <<  rk2out[i]<< setw(15) << setprecision (6) << fixed  <<rk4out[i] << setw(15)<<endl;
	  a=a+h; 
        }
      os.close();
      cout << "File out.dat written successfully" << endl;
    }
}