program main

!*****************************************************************************80
!
!! MAIN is the main program for REJOIN_TEST.
!
!  Discussion:
!
!    REJOIN_TEST tests the REJOIN library.
!
!  Licensing:
!
!    This code is distributed under the GNU LGPL license.
!
!  Modified:
!
!    13 May 1999
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer ( kind = 4 ), parameter :: npx = 4
  integer ( kind = 4 ), parameter :: npy = 2
  integer ( kind = 4 ), parameter :: nsc = 8
  integer ( kind = 4 ), parameter :: nx_global = 100
  integer ( kind = 4 ), parameter :: ny_global = 100

  integer ( kind = 4 ), parameter :: nx_local = nx_global / npx
  integer ( kind = 4 ), parameter :: ny_local = ny_global / npy

  integer ( kind = 4 ) i_status
  integer ( kind = 4 ) john
  character ( len = 15 ) pform
  character ( len = 15 ) sform
  real ( kind = 4 ) time

  call timestamp ( )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'REJOIN_TEST'
  write ( *, '(a)' ) '  FORTRAN90 version'
  write ( *, '(a)' ) '  "Rejoin" a set of data files associated with'
  write ( *, '(a)' ) '  a decomposition of a rectangular array of data'
  write ( *, '(a)' ) '  into rectangular subarrays associated with'
  write ( *, '(a)' ) '  NPX by NPY processors.'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  The original region had a grid point shape of '
  write ( *, '(i6,a,i6)' ) nx_global, ' by ', ny_global
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  The processor array has the shape:'
  write ( *, '(i6,a,i6)' ) npx, ' by ', npy
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Therefore, the subarrays have shape:'
  write ( *, '(i6,a,i6)' ) nx_local, ' by ', ny_local

  pform = 'formatted'
  sform = 'formatted'

  write ( *, * ) ' '
  write ( *, * ) '  The input parallel files are assumed to be ' &
    // trim ( pform )
  write ( *, * ) '  The output serial file will be ' // trim ( sform )
!
!  Set JOHN to
!    0, do nothing
!    1, convert L files only.
!    2, convert       T files only.
!    3, convert L and T files.
!
  john = 1

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Requested conversion:'

  if ( john == 0 ) then
    write ( *, '(a)' ) '    NOTHING.'
  else if ( john == 1 ) then
    write ( *, '(a)' ) '    Convert FIELD_L files.'
  else if ( john == 2 ) then
    write ( *, '(a)' ) '    Convert FIELD_T files.'
  else if ( john == 3 ) then
    write ( *, '(a)' ) '    Convert FIELD_L and FIELD_T files.'
  end if
!
!  Handle the FIELD_L files.
!  There is only one set of these.
!
  if ( john == 1 .or. john == 3 ) then

    i_status = 1

    time = 0.0E+00

    call rejoin_save ( i_status, npx, npy, nsc, nx_global, &
      ny_global, nx_local, ny_local, time, pform, sform )

  end if
!
!  Handle the FIELD_T files.
!  There could be one set of these for each time step.
!
  if ( john == 2 .or. john == 3 ) then

    i_status = 0

    time = 0.0E+00

    call rejoin_save ( i_status, npx, npy, nsc, nx_global, &
      ny_global, nx_local, ny_local, time, pform, sform )

  end if
!
!  Terminate.
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'REJOIN_TEST'
  write ( *, '(a)' ) '  Normal end of execution.'
  write ( *, '(a)' ) ' '
  call timestamp ( )

  stop 0
end