#include <iostream>
#include <fstream>
#include <iomanip>
#include <math.h>

#ifndef M_PI
#define M_PI 3.1415926
#endif

void dump(std::ostream& out, double* data, int n,
             double* x=NULL, double* y=NULL)
{
   
   for(int i=0; i<n; i++)
   {
      if (x!=NULL)
         out << std::scientific << x[i] << " ";
      if (y!=NULL)
         out << std::scientific << y[i] << " ";
      out << std::scientific << data[i] << std::endl;
   }
}

inline void dump_to_file(const char* file_name, double* data, int n,
             double *x=NULL, double *y=NULL)
{
   std::ofstream out(file_name);
   dump(out, data, n, x, y);
   out.flush();
   out.close();
}

int main()
{
   int N, i,j,k;
   double x_coord, y_coord;

   std::cout << "Enter the dimension of the vector: ";
   std::cin >> N;
   std::cout << std::endl;

   double*  x = new double[N];
   double*  b = new double[N];

   for (i=0; i<N; i++)
   {
      x[i] = i*(2*M_PI/(N-1));
      b[i] = sin(x[i]);
   }

   dump_to_file("data_1d.out", b, N, x);

   delete b; b = new double[N*N];

   for (k=0; k<N*N; k++)
   {
      i = k/N; j = k%N;
      y_coord = i*(1.0/(N-1)); x_coord = j*(1.0/(N-1));
      
      b[k] = sin(2*M_PI*x_coord*y_coord);
   }
   
   dump_to_file("data_2d.out", b, N*N);   

   delete x;
   delete b;
}