program main

!*****************************************************************************80
!
!! cvtp_test() tests cvtp().
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    28 July 2016
!
!  Author:
!
!    John Burkardt
!
  implicit none

  call timestamp ( )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'cvtp_test():'
  write ( *, '(a)' ) '  FORTRAN90 version'
  write ( *, '(a)' ) '  Test cvtp().'

  call cvtp_modular_test ( )
  call cvtp_nonmodular_test ( )
!
!  Terminate.
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'cvtp_test():'
  write ( *, '(a)' ) '  Normal end of execution.'
  write ( *, '(a)' ) ' '
  call timestamp ( )

  stop 0
end
subroutine cvtp_modular_test ( )

!*****************************************************************************80
!
!! CVTP_MODULAR_TEST tests CVTP with MODULAR TRUE.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    25 July 2016
!
!  Author:
!
!    John Burkardt
!
  implicit none

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

  integer, parameter :: m = 2
  integer, parameter :: n = 400

  real ( kind = rk ) change_l2
  integer, parameter :: cvt_steps = 50
  character ( len = 80 ) :: file_out_name = 'cvtp_1x1.txt'
  real ( kind = rk ) generator(m,n)
  integer i
  logical modular
  logical reset
  integer sample_num_cvt
  integer, parameter :: sample_num_steps = 50
  real ( kind = rk ) width(m)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'CVTP_MODULAR_TEST'
  write ( *, '(a)' ) '  CVTP can compute a periodic Centroidal Voronoi Tessellation'
  write ( *, '(a)' ) '  We set MODULAR to TRUE to do this.'

  generator(1:m,1:n) = 0.0D+00
  modular = .true.
  reset = .true.
  sample_num_cvt = 100000
  width = (/ 1.0D+00, 1.0D+00 /)

  write ( *, '(a)' ) ' '
  write ( *, '(a,i12)' ) '  Spatial dimension M =        ', m
  write ( *, '(a,i12)' ) '  Number of generators =       ', n
  write ( *, '(a,l)'   ) '  MODULAR arithmetic option =  ', modular
  write ( *, '(a,i6)'  ) '  Number of sample points =    ', sample_num_cvt
  write ( *, '(a,i6)'  ) '  Number of sample steps =     ', sample_num_steps
!
!  Initialize the generators.
!
  call cvtp_region_sampler ( m, n, generator, width )

  do i = 1, cvt_steps

    call cvtp_iteration ( m, n, generator, width, modular, sample_num_cvt, &
      change_l2 )

  end do

  call r8mat_write ( file_out_name, m, n, generator )

  return
end
subroutine cvtp_nonmodular_test ( )

!*****************************************************************************80
!
!! CVTP_NONMODULAR_TEST tests CVTP with MODULAR false.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    25 July 2016
!
!  Author:
!
!    John Burkardt
!
  implicit none

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

  integer, parameter :: m = 2
  integer, parameter :: n = 400

  real ( kind = rk ) change_l2
  integer, parameter :: cvt_steps = 50
  character ( len = 80 ) :: file_out_name = 'cvt_1x1.txt'
  real ( kind = rk ) generator(m,n)
  integer i
  logical modular
  logical reset
  integer sample_num_cvt
  integer, parameter :: sample_num_steps = 50
  real ( kind = rk ) width(m)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'CVTP_NONMODULAR_TEST'
  write ( *, '(a)' ) '  CVTP can compute a periodic Centroidal Voronoi Tessellation.'
  write ( *, '(a)' ) '  But here, we turn modularity OFF.'

  generator(1:m,1:n) = 0.0D+00
  modular = .false.
  reset = .true.
  sample_num_cvt = 100000
  width = (/ 1.0D+00, 1.0D+00 /)

  write ( *, '(a)' ) ' '
  write ( *, '(a,i12)' ) '  Spatial dimension M =        ', m
  write ( *, '(a,i12)' ) '  Number of generators =       ', n
  write ( *, '(a,l)'   ) '  MODULAR arithmetic option =  ', modular
  write ( *, '(a,i6)'  ) '  Number of sample points =    ', sample_num_cvt
  write ( *, '(a,i6)'  ) '  Number of sample steps =     ', sample_num_steps
!
!  Initialize the generators.
!
  call cvtp_region_sampler ( m, n, generator, width )

  do i = 1, cvt_steps
    call cvtp_iteration ( m, n, generator, width, modular, sample_num_cvt, &
      change_l2 )

  end do

  call r8mat_write ( file_out_name, m, n, generator )

  return
end
subroutine timestamp ( )

!*****************************************************************************80
!
!! timestamp() prints the current YMDHMS date as a time stamp.
!
!  Example:
!
!    31 May 2001   9:45:54.872 AM
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    18 May 2013
!
!  Author:
!
!    John Burkardt
!
  implicit none

  character ( len = 8 ) ampm
  integer d
  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
  integer values(8)
  integer y

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

  return
end