program main

!*****************************************************************************80
!
!! triangle_grid_test() tests triangle_grid().
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    01 September 2010
!
!  Author:
!
!    John Burkardt
!
  implicit none

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

  call timestamp ( )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'triangle_grid_test():'
  write ( *, '(a)' ) '  Fortran90 version'
  write ( *, '(a)' ) '  Test triangle_grid().'

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

  stop 0
end
subroutine test01 ( )

!*****************************************************************************80
!
!! TEST01 tests TRIANGLE_GRID.
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    01 September 2010
!
!  Author:
!
!    John Burkardt
!
  implicit none

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

  integer, parameter :: n = 10
  integer, parameter :: ng = ((n+1)*(n+2))/2

  character ( len = 255 ) filename
  integer j
  real ( kind = rk ) t(2,3)
  real ( kind = rk ) tg(2,ng)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST01'
  write ( *, '(a)' ) '  TRIANGLE_GRID can define a triangular grid of points'
  write ( *, '(a)' ) '  with N+1 points on a side, based on any triangle.'

  t = reshape ( (/ &
    0.0D+00, 0.0D+00, &
    1.0D+00, 0.0D+00, &
    0.5D+00, 0.86602540378443860D+00 /), (/ 2, 3 /) )

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Defining triangle:'
  write ( *, '(a)' ) '     J      X      Y'
  write ( *, '(a)' ) ' '
  do j = 1, 3
    write ( *, '(2x,i4,2x,g14.6,2x,g14.6)' ) j, t(1:2,j)
  end do
  call triangle_grid ( n, t, tg )

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '     J      X      Y'
  write ( *, '(a)' ) ' '
  do j = 1, ng
    write ( *, '(2x,i4,2x,g14.6,2x,g14.6)' ) j, tg(1:2,j)
  end do

  filename = 'triangle_grid_test01.xy'

  open ( unit = 1, file = filename, status = 'replace' )
  do j = 1, ng
    write ( 1, '(2x,g14.6,2x,g14.6)' ) tg(1:2,j)
  end do
  close ( unit = 1 )

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Data written to "' // trim ( filename ) // '".'

  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

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

  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