Usage: <tt>input = <i>pn</i> incnfile = <i>fname</i> readpath</tt>

<p>
Read path from file.
There are three paths in the MD++/ising model: <tt>pathA</tt>, <tt>pathB</tt>, <tt>pathC</tt>.
Which one gets written depends on the value of <tt><i>pn</i></tt>
(1 for <tt>pathA</tt>, 2 for <tt>pathB</tt>, 3 for <tt>pathC</tt>).

<p>
Also see <tt>writepath</tt>.

