program main

!*****************************************************************************80
!
!! grf_io_test() tests grf_io().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    11 January 2009
!
!  Author:
!
!    John Burkardt
!
  implicit none

  call timestamp ( )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'grf_io_test():'
  write ( *, '(a)' ) '  FORTRAN90 version'
  write ( *, '(a)' ) '  Test grf_io().'

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

  stop 0
end
subroutine test01 ( )

!*****************************************************************************80
!
!! TEST01 tests GRF_HEADER_WRITE and GRF_DATA_WRITE.
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    12 January 2009
!
!  Author:
!
!    John Burkardt
!
  implicit none

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

  integer edge_num
  integer, allocatable :: edge_data(:)
  integer, allocatable :: edge_pointer(:)
  integer node_num
  character ( len = 80 ) :: output_filename = 'coxeter.grf'
  real ( kind = rk ), allocatable :: xy(:,:)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST01():'
  write ( *, '(a)' ) '  GRF_HEADER_WRITE writes the header of a GRF file.'
  write ( *, '(a)' ) '  GRF_DATAWRITE writes the data of a GRF file.'

  call grf_example_size ( node_num, edge_num )

  call grf_header_print ( node_num, edge_num )

  allocate ( edge_pointer(1:node_num+1) )
  allocate ( edge_data(1:edge_num) )
  allocate ( xy(1:2,1:node_num) )

  call grf_example ( node_num, edge_num, edge_pointer, edge_data, xy )

  call grf_write ( output_filename, node_num, edge_num, edge_pointer, &
    edge_data, xy )

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  Wrote the GRF file "' // trim ( output_filename ) // '".'

  deallocate ( edge_data )
  deallocate ( edge_pointer )
  deallocate ( xy )

  return
end
subroutine test02 ( )

!*****************************************************************************80
!
!! TEST02 tests GRF_HEADER_READ and GRF_DATA_READ.
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    11 January 2009
!
!  Author:
!
!    John Burkardt
!
  implicit none

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

  integer edge_num
  character ( len = 80 ) :: input_filename = 'coxeter.grf'
  integer, allocatable :: edge_data(:)
  integer, allocatable :: edge_pointer(:)
  integer node_num
  real ( kind = rk ), allocatable :: xy(:,:)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST02'
  write ( *, '(a)' ) '  GRF_HEADER_READ reads the header of a GRF file.'
  write ( *, '(a)' ) '  GRF_DATA_READ reads the data of a GRF file.'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  Reading the GRF file "' // trim ( input_filename ) // '".'

  call grf_header_read ( input_filename, node_num, edge_num )

  call grf_header_print ( node_num, edge_num )

  allocate ( edge_pointer(1:node_num+1) )
  allocate ( edge_data(1:edge_num) )
  allocate ( xy(1:2,1:node_num) )

  call grf_data_read ( input_filename, node_num, edge_num, edge_pointer, &
    edge_data, xy )

  call grf_data_print ( node_num, edge_num, edge_pointer, edge_data, xy )

  deallocate ( edge_data )
  deallocate ( edge_pointer )
  deallocate ( xy )

  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