function?[hd?D]?=?HausdorffDist（PQ）
%?Calculates?the?Hausdorff?Distance?between?P?and?Q
%
%?hd?=?HausdorffDist（PQ）
%?[hd?D]?=?HausdorffDist（PQ）
%
%?Calculates?the?Hausdorff?Distance?hd??between?two?sets?of?points?P?and?Q
%?（which?could?be?two?trajectories）?in?two?dimensions.?Sets?P?and?Q?must
%?therefore?be?matricies?with?an?equal?number?of?columns?（dimensions）
%?though?not?necessarily?an?equal?number?of?rows?（observations）.
%
%?The?Directional?Hausdorff?Distance?（dhd）?is?defined?as:
%?dhd（PQ）?=?max?p?c?P?[?min?q?c?Q?[?||p-q||?]?].
%?Intuitively?dhd?finds?the?point?p?from?the?set?P?that?is?farthest?from?any
%?point?in?Q?and?measures?the?distance?from?p?to?its?nearest?neighbor?in?Q.
%?
%?The?Hausdorff?Distance?is?defined?as?max{dhd（PQ）dhd（QP）}
%
%?D?is?the?mat