program plot_fit_range
      real x(1001),y(1001)
      integer pgopen
      if(pgopen('/xwin')<=0)stop
      xmax=2*3.14159
      xmin=0.0
      dx=(xmax-xmin)/1000
      do i=1,1001
        x(i)=(i-1)*dx
        y(i)=sin(x(i))
      end do
      ymax=sin(0.0)
      ymin=ymax
      do i=2,1001
        if(y(i)>ymax)ymax=y(i)
        if(y(i)<ymin)ymin=y(i)
      end do
      call pgenv(xmin,xmax,ymin-0.1,ymax+0.1,0,0)
      call pgline(1001,x,y)
      call pgclos
      end