program main

!*****************************************************************************80
!
!! niederreiter2_test() tests niederreiter2().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    21 January 2007
!
!  Author:
!
!    John Burkardt
!
  implicit none

  call timestamp ( )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'niederreiter2_test():'
  write ( *, '(a)' ) '  FORTRAN90 version'
  write ( *, '(a)' ) '  Test niederreiter2().'

  call test01 ( )
  call test02 ( )
!
!  Terminate.
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'niederreiter2_test():'
  write ( *, '(a)' ) '  Normal end of execution.'
  write ( *, '(a)' ) ' '
  call timestamp ( )

  stop 0
end
subroutine test01 ( )

!*****************************************************************************80
!
!! TEST01 tests NIEDERREITER2.
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    28 August 2007
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: dim_max = 4

  integer dim_num
  integer i
  real ( kind = rk ) r(dim_max)
  integer seed
  integer seed_in
  integer seed_out

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST01'
  write ( *, '(a)' ) '  NIEDERREITER2 computes the next element of '
  write ( *, '(a)' ) '  a Niederreiter quasirandom sequence using base 2.'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  In this test, we call NIEDERREITER2 repeatedly.'

  do dim_num = 2, dim_max

    seed = 0

    write ( *, '(a)' ) ' '
    write ( *, '(a,i8)' ) '  Using dimension DIM_NUM =   ', dim_num
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) '    Seed    Seed     Niederreiter2'
    write ( *, '(a)' ) '      In     Out'
    write ( *, '(a)' ) ' '
    do i = 0, 110
      seed_in = seed
      call niederreiter2 ( dim_num, seed, r )
      seed_out = seed
      if ( i <= 11 .or. 95 <= i ) then
        write ( *, '(i8,i8,4f10.4)' ) seed_in, seed_out, r(1:dim_num)
      else if ( i == 12 ) then
        write ( *, '(a)' ) '......................'
      end if
    end do

  end do

  return
end
subroutine test02 ( )

!*****************************************************************************80
!
!! TEST02 tests NIEDERREITER2.
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    28 August 2007
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer, parameter :: dim_num = 3

  integer i
  real ( kind = rk ) r(dim_num)
  integer seed
  integer seed_in
  integer seed_out

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST02'
  write ( *, '(a)' ) '  NIEDERREITER2 computes the next element of '
  write ( *, '(a)' ) '  a Niederreiter quasirandom sequence using base 2.'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  In this test, we demonstrate how the SEED can be'
  write ( *, '(a)' ) '  manipulated to skip ahead in the sequence, or'
  write ( *, '(a)' ) '  to come back to any part of the sequence.'

  write ( *, '(a)' ) ' '
  write ( *, '(a,i8)' ) '  Using dimension DIM_NUM =   ', dim_num

  seed = 0

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '    Seed    Seed     Niederreiter2'
  write ( *, '(a)' ) '      In     Out'
  write ( *, '(a)' ) ' '
  do i = 0, 10
    seed_in = seed
    call niederreiter2 ( dim_num, seed, r )
    seed_out = seed
    write ( *, '(2i8,4f10.4)' ) seed_in, seed_out, r(1:dim_num)
  end do

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Jump ahead by increasing SEED:'
  write ( *, '(a)' ) ' '

  seed = 100

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '    Seed    Seed     Niederreiter2'
  write ( *, '(a)' ) '      In     Out'
  write ( *, '(a)' ) ' '
  do i = 1, 5
    seed_in = seed
    call niederreiter2 ( dim_num, seed, r )
    seed_out = seed
    write ( *, '(2i8,4f10.4)' ) seed_in, seed_out, r(1:dim_num)
  end do

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Jump back by decreasing SEED:'
  write ( *, '(a)' ) ' '

  seed = 3

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '    Seed    Seed     Niederreiter2'
  write ( *, '(a)' ) '      In     Out'
  write ( *, '(a)' ) ' '
  do i = 0, 10
    seed_in = seed
    call niederreiter2 ( dim_num, seed, r )
    seed_out = seed
    write ( *, '(2i8,4f10.4)' ) seed_in, seed_out, r(1:dim_num)
  end do

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Jump ahead by increasing SEED:'
  write ( *, '(a)' ) ' '

  seed = 98

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '    Seed    Seed     Niederreiter2'
  write ( *, '(a)' ) '      In     Out'
  write ( *, '(a)' ) ' '
  do i = 1, 5
    seed_in = seed
    call niederreiter2 ( dim_num, seed, r )
    seed_out = seed
    write ( *, '(2i8,4f10.4)' ) seed_in, seed_out, r(1:dim_num)
  end do

  return
end
subroutine timestamp ( )

!*****************************************************************************80
!
!! timestamp() prints the current YMDHMS date as a time stamp.
!
!  Example:
!
!    May 31 2001   9:45:54.872 AM
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    31 May 2001
!
!  Author:
!
!    John Burkardt
!
  implicit none

  character ( len = 8 ) ampm
  integer d
  character ( len = 8 ) date
  integer h
  integer m
  integer mm
  character ( len = 9 ), parameter, dimension(12) :: month = (/ &
    'January  ', 'February ', 'March    ', 'April    ', &
    'May      ', 'June     ', 'July     ', 'August   ', &
    'September', 'October  ', 'November ', 'December ' /)
  integer n
  integer s
  character ( len = 10 )  time
  integer values(8)
  integer y
  character ( len = 5 ) zone

  call date_and_time ( date, time, zone, values )

  y = values(1)
  m = values(2)
  d = values(3)
  h = values(5)
  n = values(6)
  s = values(7)
  mm = values(8)

  if ( h < 12 ) then
    ampm = 'AM'
  else if ( h == 12 ) then
    if ( n == 0 .and. s == 0 ) then
      ampm = 'Noon'
    else
      ampm = 'PM'
    end if
  else
    h = h - 12
    if ( h < 12 ) then
      ampm = 'PM'
    else if ( h == 12 ) then
      if ( n == 0 .and. s == 0 ) then
        ampm = 'Midnight'
      else
        ampm = 'AM'
      end if
    end if
  end if

  write ( *, '(a,1x,i2,1x,i4,2x,i2,a1,i2.2,a1,i2.2,a1,i3.3,1x,a)' ) &
    trim ( month(m) ), d, y, h, ':', n, ':', s, '.', mm, trim ( ampm )

  return
end