# include <cstdlib>
# include <ctime>
# include <iomanip>
# include <iostream>

using namespace std;

# include "kdv_exact.hpp"

int main ( );
void kdv_exact_rational_test ( );
void kdv_exact_sech_test ( );
double *r8vec_linspace_new ( int n, double a, double b );
void timestamp ( );

//****************************************************************************80

int main ( )

/******************************************************************************/
//
//  Purpose:
//
//    kdv_exact_test() tests kdv_exact().
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    02 May 2024
//
//  Author:
//
//    John Burkardt
//
{
  timestamp ( );
  cout << "\n";
  cout << "kdv_exact_test():\n";
  cout << "  C++ version\n";
  cout << "  Test kdv_exact().\n";

  kdv_exact_rational_test ( );
  kdv_exact_sech_test ( );
//
//  Terminate.
//
  cout << "\n";
  cout << "kdv_exact_test():\n";
  cout << "  Normal end of execution.\n";
  cout << "\n";
  timestamp ( );

  return 0;
}
//****************************************************************************80

void kdv_exact_rational_test ( )

//****************************************************************************80
//
//  Purpose:
//
//    kdv_exact_rational_test() tests kdv_exact_rational().
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    02 May 2024
//
//  Author:
//
//    John Burkardt
//
{

  int nt = 6;
  int nx = 6;

  int i;
  int j;
  double r;
  double *t;
  double t0;
  double tstop;
  double u;
  double ut;
  double ux;
  double uxx;
  double uxxx;
  double *x;

  cout << "\n";
  cout << "kdv_exact_rational_test():\n";
  cout << "  Test kdv_exact_rational().\n";

  kdv_parameters ( NULL, NULL, NULL, NULL, NULL, NULL, &t0, &tstop );

  cout << "\n";
  cout << "  Parameters:\n";
  cout << "    t0    = " << t0 << "\n";
  cout << "    tstop = " << tstop << "\n";

  cout << "\n";
  cout << "  Evaluate solution and residual at selected points (X,T)\n";
  
  x = r8vec_linspace_new ( nx, 0.0, 1.0 );
  t = r8vec_linspace_new ( nt, t0, tstop );

  cout << "\n";
  cout << "      T       X       U(X,T)      Resid(X,T)\n";
  cout << "\n";

  for ( i = 0; i < nt; i++ )
  {
    for ( j = 0; j < nx; j++ )
    {
      kdv_exact_rational ( x[j], t[i], &u, &ut, &ux, &uxx, &uxxx );
      r = kdv_residual ( u, ut, ux, uxxx );

      if ( t[i] == 0.0 && x[j] == 0.0 )
      {
        cout << setw(14) << t[i]
             << setw(14) << x[j]
             << "     Undefined     Undefined\n";
      }
      else
      {
        cout << setw(14) << t[i]
             << setw(14) << x[j]
             << setw(14) << u
             << setw(14) << r << "\n";
      }
    }
    cout << "\n";
  }

  delete [] t;
  delete [] x;

  return;
}
//****************************************************************************80

void kdv_exact_sech_test ( )

//****************************************************************************80
//
//  Purpose:
//
//    kdv_exact_sech_test() tests kdv_exact_sech().
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    02 May 2024
//
//  Author:
//
//    John Burkardt
//
{
  int nt = 6;
  int nx = 6;

  double a;
  int i;
  int j;
  double r;
  double *t;
  double t0;
  double tstop;
  double u;
  double ut;
  double ux;
  double uxx;
  double uxxx;
  double v;
  double *x;

  cout << "\n";
  cout << "kdv_exact_sech_test():\n";
  cout << "  Test kdv_exact_sech().\n";

  kdv_parameters ( NULL, NULL, NULL, NULL, &a, &v, &t0, &tstop );

  cout << "\n";
  cout << "  Parameters:\n";
  cout << "    a     = " << a << "\n";
  cout << "    v     = " << v << "\n";
  cout << "    t0    = " << t0 << "\n";
  cout << "    tstop = " << tstop << "\n";

  cout << "\n";
  cout << "  Evaluate solution and residual at selected points (X,T)\n";
  
  x = r8vec_linspace_new ( nx, 0.0, 1.0 );
  t = r8vec_linspace_new ( nt, t0, tstop );

  cout << "\n";
  cout << "      T       X       U(X,T)      Resid(X,T)\n";
  cout << "\n";

  for ( i = 0; i < nt; i++ )
  {
    for ( j = 0; j < nx; j++ )
    {
      kdv_exact_sech ( x[j], t[i], &u, &ut, &ux, &uxx, &uxxx );
      r = kdv_residual ( u, ut, ux, uxxx );

      if ( t[i] == 0.0 && x[j] == 0.0 )
      {
        cout << setw(14) << t[i]
             << setw(14) << x[j]
             << "     Undefined     Undefined\n";
      }
      else
      {
        cout << setw(14) << t[i]
             << setw(14) << x[j]
             << setw(14) << u
             << setw(14) << r << "\n";
      }
    }
    cout << "\n";
  }

  delete [] t;
  delete [] x;

  return;
}
//****************************************************************************80

double *r8vec_linspace_new ( int n, double a_first, double a_last )

//****************************************************************************80
//
//  Purpose:
//
//    r8vec_linspace_new() creates a vector of linearly spaced values.
//
//  Discussion:
//
//    An R8VEC is a vector of R8's.
//
//    4 points evenly spaced between 0 and 12 will yield 0, 4, 8, 12.
//
//    In other words, the interval is divided into N-1 even subintervals,
//    and the endpoints of intervals are used as the points.
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    29 March 2011
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int N, the number of entries in the vector.
//
//    Input, double A_FIRST, A_LAST, the first and last entries.
//
//    Output, double R8VEC_LINSPACE_NEW[N], a vector of linearly spaced data.
//
{
  double *a;
  int i;

  a = new double[n];

  if ( n == 1 )
  {
    a[0] = ( a_first + a_last ) / 2.0;
  }
  else
  {
    for ( i = 0; i < n; i++ )
    {
      a[i] = ( ( double ) ( n - 1 - i ) * a_first 
             + ( double ) (         i ) * a_last ) 
             / ( double ) ( n - 1     );
    }
  }
  return a;
}
//****************************************************************************80

void timestamp ( )

//****************************************************************************80
//
//  Purpose:
//
//    timestamp() prints the current YMDHMS date as a time stamp.
//
//  Example:
//
//    31 May 2001 09:45:54 AM
//
//  Licensing:
//
//    This code is distributed under the MIT license. 
//
//  Modified:
//
//    19 March 2018
//
//  Author:
//
//    John Burkardt
//
{
# define TIME_SIZE 40

  static char time_buffer[TIME_SIZE];
  const struct std::tm *tm_ptr;
  std::time_t now;

  now = std::time ( NULL );
  tm_ptr = std::localtime ( &now );

  std::strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm_ptr );

  std::cout << time_buffer << "\n";

  return;
# undef TIME_SIZE
}