program dessiner
    use plplot
    implicit none

    integer            :: i
    real               :: a, b, c, d

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

    call plsdev('xwin')
    call plinit ()

    call plenv(-2.2, 2.2, -2.2, 2.2, 0, 1)

    a = 0
    b = 0
    c = 0
    d = 0
    do i=1, 100
      a = a + 0.01
      b = b + 0.02
      call dessin_1 (a, b, 12)
      c = c + 0.03
      d = d + 0.04
      call dessin_1 (c, d, 13)
    enddo

    call plend

contains                ! -----------------------------
!------------------------------------------------------
subroutine dessin_1 (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 1'
    amp = 2.0
    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)

end subroutine
!------------------------------------------------------
subroutine dessin_2 ()

    print *, 'dessin 2'

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

end program