program dessiner
    use plplot
    implicit none

    integer            :: i

    character(len=80) :: version
    call plgver(version)
    write (*,'(a,a)') 'plPlot version: ', trim(version)

    ! call dessin_X11 (0.00, 1.51, 11)
    call dessin_dans_un_fichier ()

contains                ! -----------------------------
!------------------------------------------------------
subroutine dessin_X11 (sha, shb, color)
    real, intent(in)      :: sha, shb
    integer, intent(in)   :: color

    integer, parameter    :: lg = 2000
    real                  :: x(lg), y(lg)
    real                  :: k, amp
    integer               :: i

    print *, 'dessin X11:', sha, shb, color

    call plsdev('xwin')
    call plinit ()
    call plenv (-2.1, 2.1, -2.1, 2.1, 1, 2)

    amp = 2.16
    do i = 1, lg
	k = real(i)/real(lg) * 6.2832 * 4.0
        x(i) = amp * sin((k+sha)*5)
        y(i) = amp * cos((k+shb)*3)
    enddo
    ! print *, k, x(i), y(i)

    call plcol0 (15)         ! pure white
    call pllab  ("Fuzzfactor", "Yoyodines", "Some nice plots from tTh")
    call plcol0 (color)
    call plline (x, y)

    call plend

end subroutine
!------------------------------------------------------
!-              _    __    ___     ___            ___
!-       __ _  (_)  / _|  ( _ )   / _ \    __ _  |__ \
!-      / _` | | | | |_   / _ \  | (_) |  / _` |   / /
!-     | (_| | | | |  _| | (_) |  \__, | | (_| |  |_|
!-      \__, | |_| |_|    \___/     /_/   \__,_|  (_)
!-      |___/

subroutine dessin_dans_un_fichier ()

    integer, parameter       :: nbpts = 40
    real                     :: x(nbpts), y(nbpts)
    integer                  :: frame, i
    character(len=89)        :: filename
    character(len=89)        :: buffer
    character(len=3)         :: str

    print *, 'Dessin dans un fichier'

    do i=1, nbpts
      x(i) = 8.50 * (rand() - 0.5000)
      y(i) = 8.50 * (rand() - 0.5000)
    enddo

    do frame= 0, 149
      write (filename, "(a, i4.4, a)") "WS/A", frame, ".png"
      print *, frame, '    =>    ', trim(filename)
      call plsdev   ('pngcairo')
      call plsfnam  (trim(filename))
      call plinit   ()
      call plenv    (-10., 10., -10., 10., 0, 1)
      call plcol0   (3)
        do i=1, nbpts
        x(i) = x(i) + (rand() - 0.5000)
        y(i) = y(i) + (rand() - 0.5000)
        call plline (x, y)
      enddo
      write(buffer, "(i3.3)") frame
      str = trim(buffer)
      call plcol0   (15)
      call plstring (x, y, buffer)

      call plend
    enddo



end subroutine
!------------------------------------------------------

end program