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

# include "asa245.hpp"

using namespace std;

int main ( );
void test01 ( );
void test02 ( );
void test03 ( );
void timestamp ( );

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

int main ( )

//****************************************************************************80
//
//  Purpose:
//
//    asa245_test() tests asa245().
//
//  Licensing:
//
//    This code is distributed under the MIT license. 
//
//  Modified:
//
//    25 September 2014
//
//  Author:
//
//    John Burkardt
//
{
  timestamp ( );
  cout << "\n";
  cout << "asa245_test():\n";
  cout << "  C++ version\n";
  cout << "  Test asa245().\n";

  test01 ( );
  test02 ( );
  test03 ( );
//
//  Terminate.
//
  cout << "\n";
  cout << "asa245_test():\n";
  cout << "  Normal end of execution.\n";
  cout << "\n";
  timestamp ( );

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

void test01 ( )

//****************************************************************************80
//
//  Purpose:
//
//    test01() tests alngam().
//
//  Licensing:
//
//    This code is distributed under the MIT license. 
//
//  Modified:
//
//    15 January 2008
//
//  Author:
//
//    John Burkardt
//
{
  double fx;
  double fx2;
  int ifault;
  int n_data;
  double x;

  cout << "\n";
  cout << "test01():\n";
  cout << "  alngam() computes the logarithm of the \n";
  cout << "  Gamma function.  We compare the result\n";
  cout << "  to tabulated values.\n";
  cout << "\n";
  cout << "          X                     "
       << "FX                        FX2\n";
  cout << "                                "
       << "(Tabulated)               (ALNGAM)                DIFF\n";
  cout << "\n";

  n_data = 0;

  for ( ; ; )
  {
    gamma_log_values ( n_data, x, fx );

    if ( n_data == 0 )
    {
      break;
    }

    fx2 = alngam ( x, ifault );

    cout << "  " << setprecision(16) << setw(24) << x
         << "  " << setprecision(16) << setw(24) << fx
         << "  " << setprecision(16) << setw(24) << fx2
         << "  " << setprecision(4) << setw(10) << fabs ( fx - fx2 ) << "\n";
  }

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

void test02 ( )

//****************************************************************************80
//
//  Purpose:
//
//    test02() tests lngamma().
//
//  Licensing:
//
//    This code is distributed under the MIT license. 
//
//  Modified:
//
//    15 January 2008
//
//  Author:
//
//    John Burkardt
//
{
  double fx;
  double fx2;
  int ier;
  int n_data;
  double x;

  cout << "\n";
  cout << "test02():\n";
  cout << "  lngamma() computes the logarithm of the \n";
  cout << "  Gamma function.  We compare the result\n";
  cout << "  to tabulated values.\n";
  cout << "\n";
  cout << "          X                     "
      << "FX                        FX2\n";
  cout << "                                "
       << "(Tabulated)               (LNGAMMA)                DIFF\n";
  cout << "\n";

  n_data = 0;

  for ( ; ; )
  {
    gamma_log_values ( n_data, x, fx );

    if ( n_data == 0 )
    {
      break;
    }

    fx2 = lngamma ( x, ier );

    cout << "  " << setprecision(16) << setw(24) << x
         << "  " << setprecision(16) << setw(24) << fx
         << "  " << setprecision(16) << setw(24) << fx2
         << "  " << setprecision(4) << setw(10) << fabs ( fx - fx2 ) << "\n";
  }

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

void test03 ( )

//****************************************************************************80
//
//  Purpose:
//
//    test03() tests lgamma().
//
//  Licensing:
//
//    This code is distributed under the MIT license. 
//
//  Modified:
//
//    25 September 2014
//
//  Author:
//
//    John Burkardt
//
{
  double fx;
  double fx2;
  int n_data;
  double x;

  cout << "\n";
  cout << "test03()\n";
  cout << "  lgamma() computes the logarithm of the \n";
  cout << "  Gamma function.\n";
  cout << "  lgamma() is available with the G++ compiler.\n";
  cout << "  Compare the result to tabulated values.\n";
  cout << "\n";
  cout << "          X                     "
      << "FX                        FX2\n";
  cout << "                                "
       << "(Tabulated)               (LNGAMMA)                DIFF\n";
  cout << "\n";

  n_data = 0;

  for ( ; ; )
  {
    gamma_log_values ( n_data, x, fx );

    if ( n_data == 0 )
    {
      break;
    }

    fx2 = lgamma ( x );

    cout << "  " << setprecision(16) << setw(24) << x
         << "  " << setprecision(16) << setw(24) << fx
         << "  " << setprecision(16) << setw(24) << fx2
         << "  " << setprecision(4) << setw(10) << fabs ( fx - fx2 ) << "\n";
  }

  return;
}
//****************************************************************************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:
//
//    24 September 2003
//
//  Author:
//
//    John Burkardt
//
{
# define TIME_SIZE 40

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

  now = time ( NULL );
  tm = localtime ( &now );

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

  cout << time_buffer << "\n";

  return;
# undef TIME_SIZE
}