program read_range_plot_array
      real x(10001), y(10001)
      character*20 user_filename

      write(*,*)'Which file to plot?'
      read(*,*)user_filename

      open(unit=10,file=user_filename)

      read(10,*)n
      if(n>10001)then
        write(*,*)'too many points for this program'
        stop
      endif

      read(10,*)x(1),y(1)
      xmin=x(1)
      xmax=x(1)
      ymin=y(1)
      ymax=y(1)
      do i=2,n
        read(10,*)x(i),y(i)
        if(x(i)>xmax)xmax=x(i)
        if(x(i)<xmin)xmin=x(i)
        if(y(i)>ymax)ymax=y(i)
        if(y(i)<ymin)ymin=y(i)
      end do

      close(10)
c     open(unit=10,file=user_filename)
C     rewind(10)
c     read(10,*)n

      if(pgopen('/xwin')<=0)stop
      call pgenv(xmin,xmax,ymin,ymax, 0,0)

c     do i=1,n
c       read(10,*)x,y
c       call pgpt(1,x,y,20)
c     end do

      call pgline(n,x,y)

      call pgclos

      end