%% SOBOL_TEST05 tests I4_SOBOL.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    16 February 2005
%
%  Author:
%
%    John Burkardt
%
  clear

  fprintf ( 1, '\n' );
  fprintf ( 1, 'SOBOL_TEST05\n' );
  fprintf ( 1, '  I4_SOBOL computes the next element of a Sobol sequence.\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  In this test, we demonstrate how the SEED can be\n' );
  fprintf ( 1, '  manipulated to skip ahead in the sequence, or\n' );
  fprintf ( 1, '  to come back to any part of the sequence.\n' );
  fprintf ( 1, '\n' );

  dim_num = 3;

  fprintf ( 1, '\n' );
  fprintf ( 1, '  Using dimension DIM_NUM =   %d\n', dim_num );

  seed = 0;

  fprintf ( 1, '\n' );
  fprintf ( 1, '  Seed  Seed   I4_SOBOL\n' );
  fprintf ( 1, '  In    Out\n' );
  fprintf ( 1, '\n' );

  for i = 0 : 10
    [ r, seed_out ] = i4_sobol ( dim_num, seed );
    fprintf ( 1, '%6d %6d  ', seed, seed_out );
    for j = 1 : dim_num
      fprintf ( 1, '%10f  ', r(j) );
    end
    fprintf ( 1, '\n' );
    seed = seed_out;
  end

  fprintf ( 1, '\n' );
  fprintf ( 1, '  Jump ahead by increasing SEED:\n' );
  fprintf ( 1, '\n' );

  seed = 100;

  fprintf ( 1, '\n' );
  fprintf ( 1, '  Seed  Seed   I4_SOBOL\n' );
  fprintf ( 1, '  In    Out\n' );
  fprintf ( 1, '\n' );

  for i = 1 : 5
    [ r, seed_out ] = i4_sobol ( dim_num, seed );
    fprintf ( 1, '%6d %6d  ', seed, seed_out );
    for j = 1 : dim_num
      fprintf ( 1, '%10f  ', r(j) );
    end
    fprintf ( 1, '\n' );
    seed = seed_out;
  end

  fprintf ( 1, '\n' );
  fprintf ( 1, '  Jump back by decreasing SEED:\n' );
  fprintf ( 1, '\n' );

  seed = 3;

  fprintf ( 1, '\n' );
  fprintf ( 1, '  Seed  Seed   I4_SOBOL\n' );
  fprintf ( 1, '  In    Out\n' );
  fprintf ( 1, '\n' );

  for i = 0 : 10
    [ r, seed_out ] = i4_sobol ( dim_num, seed );
    fprintf ( 1, '%6d %6d  ', seed, seed_out );
    for j = 1 : dim_num
      fprintf ( 1, '%10f  ', r(j) );
    end
    fprintf ( 1, '\n' );
    seed = seed_out;
  end

  fprintf ( 1, '\n' );
  fprintf ( 1, '  Jump back by decreasing SEED:\n' );
  fprintf ( 1, '\n' );

  seed = 98;

  fprintf ( 1, '\n' );
  fprintf ( 1, '  Seed  Seed   I4_SOBOL\n' );
  fprintf ( 1, '  In    Out\n' );
  fprintf ( 1, '\n' );

  for i = 1 : 5
    [ r, seed_out ] = i4_sobol ( dim_num, seed );
    fprintf ( 1, '%6d %6d  ', seed, seed_out );
    for j = 1 : dim_num
      fprintf ( 1, '%10f  ', r(j) );
    end
    fprintf ( 1, '\n' );
    seed = seed_out;
  end