hammersley_dataset.cpp

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

using namespace std;

# include "hammersley.H"

int main ( void );

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

int main ( void )

//****************************************************************************80
//
//  Purpose:
//
//    MAIN is the main program for HAMMERSLEY_DATASET.
//
//  Discussion:
//
//    HAMMERSLEY_DATASET generates a Hammersley dataset and writes it to a file.
//
//    This program is meant to be used interactively.  It's also
//    possible to prepare a simple input file beforehand and use it
//    in batch mode.
//
//    The program requests input values from the user:
//
//    * DIM_NUM, the spatial dimension,
//    * N, the number of points to generate,
//    * STEP, the index of the first subsequence element to be computed.
//    * SEED(1:DIM_NUM), the sequence index corresponding to STEP = 0.
//    * LEAP(1:DIM_NUM), the successive jumps in the sequence.
//    * BASE(1:DIM_NUM), the bases (usually distinct primes or -N).
//
//    The program generates the data, writes it to the file
//
//      hammersley_DIM_NUM_N.txt
//
//    where "DIM_NUM" and "N" are the numeric values specified by the user,
//    and then asks the user for more input.   To indicate that no further
//    computations are desired, it is enough to input a nonsensical
//    value, such as -1.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    12 April 2007
//
//  Author:
//
//    John Burkardt
//
{
  int *base;
  char command[80];
  char file_out_name[80];
  int i;
  int *leap;
  int n;
  int dim_num;
  double *r;
  int *seed;
  int step;
  char *string;

  timestamp ( );

  cout << "\n";
  cout << "HAMMERSLEY_DATASET\n";
  cout << "  C++ version\n";
  cout << "\n";
  cout << "  Compiled on " << __DATE__ << " at " << __TIME__ << ".\n";
  cout << "\n";
  cout << "  Generate a Hammersley dataset.\n";
  cout << "\n";
  cout << "  This program is meant to be used interactively.\n";
  cout << "  It is also possible to prepare a simple input\n";
  cout << "  file beforehand and use it in batch mode.\n";
  cout << "\n";
  cout << "  The program requests input values from the user:\n";
  cout << "\n";
  cout << "  * DIM_NUM, the spatial dimension,\n";
  cout << "  * N, the number of points to generate,\n";
  cout << "  * STEP, the index of the first subsequence element.\n";
  cout << "  * SEED(1:DIM_NUM),the sequence element corresponding to STEP = 0\n";
  cout << "  * LEAP(1:DIM_NUM), the succesive jumps in the sequence.\n";
  cout << "  * BASE(1:DIM_NUM), the bases, usually distinct primes\n";
  cout << "    or -N (to generate values like I/N).\n";
  cout << "\n";
  cout << "  The program generates the data, writes it to the file\n";
  cout << "\n";
  cout << "    hammersley_DIM_NUM_N.txt\n";
  cout << "\n";
  cout << "  where ""DIM_NUM"" and ""N"" are the numeric values specified\n";
  cout << "  by the user, and then asks the user for more input.\n";
  cout << "\n";
  cout << "  To indicate that no further computations are\n";
  cout << "  desired, it is enough to input a nonsensical value,\n";
  cout << "  such as -1.\n";

  for ( ; ; )
  {
    cout << "  *\n";
    cout << " *\n";
    cout << "*  Ready to generate a new dataset:\n";
    cout << " *\n";
    cout << "  *\n";

    cout << "\n";
    cout << "  Enter DIM_NUM, the spatial dimension:\n";
    cout << "  (Try '2' if you have no preference.)\n";
    cout << "  (0 or any negative value terminates execution).\n";

    cin >> dim_num;

    if ( cin.rdstate ( ) )
    {
      cin.clear ( );

      cout << "\n";
      cout << "HAMMERSLEY_DATASET - Fatal error!\n";
      cout << "  An I/O error occurred while trying to read DIM_NUM.\n";
      cout << "  Abnormal end of execution.\n";
      break;
    }

    if ( !halham_dim_num_check ( dim_num ) )
    {
      cout << "\n";
      cout << "HAMMERSLEY_DATASET\n";
      cout << "  The input value of DIM_NUM = " << dim_num << "\n";
      cout << "  is interpreted as a request for termination.\n";
      cout << "  Normal end of execution.\n";
      break;
    }

    cout << "\n";
    cout << "  Enter N, the number of points to generate:\n";
    cout << "  (Try '25' if you have no preference.)\n";
    cout << "  (0 or any negative value terminates execution).\n";

    cin >> n;

    if ( cin.rdstate ( ) )
    {
      cin.clear ( );

      cout << "\n";
      cout << "HAMMERSLEY_DATASET - Fatal error!\n";
      cout << "  An I/O error occurred while trying to read N.\n";
      cout << "  Abnormal end of execution.\n";
      break;
    }

    if ( !halham_n_check ( n ) )
    {
      cout << "\n";
      cout << "HAMMERSLEY_DATASET\n";
      cout << "  The input value of N = " << n << "\n";
      cout << "  is interpreted as a request for termination.\n";
      cout << "  Normal end of execution.\n";
      break;
    }

    cout << "\n";
    cout << "  Enter STEP, the index of the first subsequence element:\n";
    cout << "  (Try '0' or '1' if you have no preference.)\n";
    cout << "  (Any negative value terminates execution).\n";

    cin >> step;

    if ( cin.rdstate ( ) )
    {
      cin.clear ( );

      cout << "\n";
      cout << "HAMMERSLEY_DATASET - Fatal error!\n";
      cout << "  An I/O error occurred while trying to read STEP.\n";
      cout << "  Abnormal end of execution.\n";
      break;
    }

    if ( !halham_step_check ( step ) )
    {
      cout << "\n";
      cout << "HAMMERSLEY_DATASET\n";
      cout << "  The input value of STEP = " << step << "\n";
      cout << "  is interpreted as a request for termination.\n";
      cout << "  Normal end of execution.\n";
      break;
    }

    base = new int[dim_num];
    leap = new int[dim_num];
    r = new double[dim_num*n];
    seed = new int[dim_num];

    cout << "\n";
    cout << "  Enter SEED(1:DIM_NUM), the starting element index\n";
    cout << "  for each coordinate\n";
    cout << "  (Try '0 0 ... 0' if you have no preference.)\n";
    cout << "  (a negative value terminates execution.)\n";

    for ( i = 0; i < dim_num; i++ )
    {
      cin >> seed[i];
      if ( cin.rdstate ( ) )
      {
        cin.clear ( );

        cout << "\n";
        cout << "HAMMERSLEY_DATASET - Fatal error!\n";
        cout << "  An I/O error occurred trying to read SEED[" << i << "].\n";
        cout << "  Abnormal end of execution.\n";
        break;
      }
    }

    i4vec_transpose_print ( dim_num, seed, "  User input:" );

    if ( !halham_seed_check ( dim_num, seed ) )
    {
      cout << "\n";
      cout << "HAMMERSLEY_DATASET\n";
      cout << "  The input value of SEED\n";
      cout << "  is interpreted as a request for termination.\n";
      cout << "  Normal end of execution.\n";
      break;
    }

    cout << "\n";
    cout << "  Enter LEAP(1:DIM_NUM), the leaping multiplier\n";
    cout << "  for each coordinate\n";
    cout << "  (Try '1 1 ... 1' if you have no preference.)\n";
    cout << "  (another choice is any prime larger than all the bases).\n";
    cout << "  (any value of 0 or less terminates execution.)\n";

    for ( i = 0; i < dim_num; i++ )
    {
      cin >> leap[i];
      if ( cin.rdstate ( ) )
      {
        cin.clear ( );

        cout << "\n";
        cout << "HAMMERSLEY_DATASET - Fatal error!\n";
        cout << "  An I/O error occurred trying to read LEAP[" << i << "].\n";
        cout << "  Abnormal end of execution.\n";
        break;
      }
    }

    i4vec_transpose_print ( dim_num, leap, "  User input:" );

    if ( !halham_leap_check ( dim_num, leap ) )
    {
      cout << "\n";
      cout << "HAMMERSLEY_DATASET\n";
      cout << "  The input value of LEAP\n";
      cout << "  is interpreted as a request for termination.\n";
      cout << "  Normal end of execution.\n";
      break;
    }

    cout << "\n";
    cout << "  Enter BASE(1:DIM_NUM), the bases, usually distinct \n";
    cout << "  primes, but any NEGATIVE base generates\n";
    cout << "  values I/BASE.";
    cout << "  (Try '-N 2 3 5 7 11 ...' if you have no preference.)\n";
    cout << "  (any value of 0 or 1 terminates execution.)\n";

    for ( i = 0; i < dim_num; i++ )
    {
      cin >> base[i];
      if ( cin.rdstate ( ) )
      {
        cin.clear ( );

        cout << "\n";
        cout << "HAMMERSLEY_DATASET - Fatal error!\n";
        cout << "  An I/O error occurred trying to read BASE[" << i << "].\n";
        cout << "  Abnormal end of execution.\n";
        break;
      }
    }

    i4vec_transpose_print ( dim_num, base, "  User input:" );

    if ( !hammersley_base_check ( dim_num, base ) )
    {
      cout << "\n";
      cout << "HAMMERSLEY_DATASET\n";
      cout << "  The input value of BASE\n";
      cout << "  is interpreted as a request for termination.\n";
      cout << "  Normal end of execution.\n";
      break;
    }

    i4_to_hammersley_sequence ( dim_num, n, step, seed, leap, base, r );

    sprintf ( file_out_name, "hammersley_%d_%d.txt", dim_num, n );

    halham_write ( dim_num, n, step, seed, leap, base, r, file_out_name );

    delete [] base;
    delete [] leap;
    delete [] r;
    delete [] seed;

    cout << "\n";
    cout << "  The data was written to the file \""
      << file_out_name << "\".\n";

  }

  cout << "\n";
  timestamp ( );

  return 0;
}