

   RReeaadd aa PPooiinntt PPrroocceessss OObbjjeecctt ffrroomm aa FFiillee

        ppinit(file)

   AArrgguummeennttss::

       file: string giving file name

   DDeessccrriippttiioonn::

        Read a file in standard format and create a point pro-
        cess object.

        The file should contain

        the number of points

        a header (ignored)

        xl xu yl yu scale

        x y (repeated n times)

   VVaalluuee::

        pp object with components `x', `y', `xl', `xu', `yl',
        `yu'

   SSiiddee EEffffeeccttss::

        Calls `ppregion' to set the domain.

   SSeeee AAllssoo::

        `ppregion'

   EExxaammpplleess::

        towns <- ppinit("towns.dat")
        par(pty="s")
        plot(Kfn(towns, 10), type="b", xlab="distance", ylab="L(t)")

