function?d?=?euclidean（abdf）
%?EUCLIDEAN?-?computes?Euclidean?distance?matrix
%
%?E?=?euclidean（AB）
%
%????A?-?（DxM）?matrix?
%????B?-?（DxN）?matrix
%????df?=?1?force?diagonals?to?be?zero;?0?（default）?do?not?force
%?
%?Returns:
%????E?-?（MxN）?Euclidean?distances?between?vectors?in?A?and?B
%
%
%?Description?:?
%????This?fully?vectorized?（VERY?FAST!）?m-file?computes?the?
%????Euclidean?distance?between?two?vectors?by:
%
%?????????????????||A-B||?=?sqrt?（?||A||^2?+?||B||^2?-?2*A.B?）
%
%?Example?:?
%????A?=?rand（400100）;?B?=?rand（400200）;
%????d?=?distance（AB）;

%?Author???:?Roland?Bunschoten
%????????????University?of?Amsterdam
%????????????Intelligent?Autonomous?Systems?（IAS）?group
%????????????Kruislaan?403??1098?SJ?Amsterdam
%????????????tel.（+31）20-5257524
%????????????bunschot@wins.uva.nl
%?Last?Rev?:?Wed?Oct?20?08:58:08?MET?DST?1999
%?Tested???:?PC?Matlab?v5.2?and?Solaris?Matlab?v5.3

%?Copyright?notice:?You?are?free?to?modify?extend?and?distribute?
%????this?code?granted?that?the?author