program plot_1
      real x(2),y(2)
      x(1)=1
      y(1)=9
      x(2)=9
      y(2)=1
      i_dummy=pgopen('/xwin')
      call pgenv(0.0,10.0,0.0,10.0,1,0)
      call pgsfs(0)
      call pgcirc(5.0,5.0,3.0)
      call pgline(2,x,y)
      call pgclos
      end