program test1

      implicit none

      integer pgopen, i
      real x(50), y(50), delta_x

      if (pgopen('/xwin') .le. 0) stop

      call pgenv(-5.0, 5.0, -5.0, 5.0, 1, 1)
      call pglab('x-axis', 'y-axis', 'This is my graph')

      delta_x = 10.0 / 50
      do i = 1,50
        x(i) = -5.0 + (i-1)*delta_x
        y(i) = 2.0
      end do

      call pgline (50, x, y)

      call pgclos

      end