function?[eigvector?eigvalue?elapse]?=?NPE（options?data）
%?NPE:?Neighborhood?Preserving?embedding
%
%???????[eigvector?eigvalue?elapse]?=?NPE（options?data）
%?
%?????????????Input:
%???????????????data????-?Data?matrix.?Each?row?vector?of?data?is?a?data?point.
%
%???????????????options?-?Struct?value?in?Matlab.?The?fields?in?options
%?????????????????????????that?can?be?set:
%
%??????????????????????NeighborMode?-??Indicates?how?to?construct?the?graph.?Choices
%???????????????????????????are:?
%???????????????????????????‘KNN‘?????-??Put?an?edge?between?two?nodes?if?and
%????????????????????????????????????????only?if?they?are?among?the?k?nearst
%????????????????????????????????????????neighbors?of?each?other.?Default
%????????????????????????????????????????option.
%???????????????????????‘Supervised‘??-??Two?variations:
%???????????????????????????????????????1.?k=0?Put?an?edge?between?two?nodes?
%??????????????????????????????????????????if?and?only?if?they?belong?to
%??????????????????????????????????????????same?class.?
%???????????????????????????????????????2.?k>0?The?distance?between?two?nodes?
%??????????????????????????????????????????in?the?same?class?will?be?smaller?than?
%??????????????????????????????????????????two?nodes?have?diff.?labels?
%??????????????????????????????????????????The?label?information?‘gnd‘?should?be
%??????????????????????????????????????????provided.
%??????????????????????????????????????????????
%???????????????????????k???????????-???The?number?of?neighbors.
%???????????????????????????????????????Default?k?=?5;
%???????????????????????gnd?????????-???The?parameter?needed?under?‘Supervised‘
%???????????????????????????????????????NeighborMode.??Colunm?vector?of?the?label
%???????????????????????????????????????information?for?each?data?point.
%
%?????????????????????????Please?see?LGE.m?for?other?options.
%
%
%?????????????Output:
%???????????????eigvector?-?Each?column?is?an?embedding?function?for?a?new
%???????????????????????????data?point?（row?vector）?x??y?=?x*eigvector
%???????????????????????????will?be?the?embedding?result?of?x.
%???????????????eigvalue??-?The?eigvalue?of?LPP?eigen-problem.?sorted?from
%???????????????????????????smallest?to?largest.?
%???????????????elapse????-?Time?spent?on?different?steps?
%?
%
%????Examples:
%
%???????
%???????
%???????fea?=?rand（5070）;
%???????gnd?=?[ones（101）;ones（151）*2;ones（101）*3;ones（151）*4];
%???????options?=?[];
%???????options.k?=?5;
%???????options.NeighborMode?=?‘Supervised‘;
%???????options.gnd?=?gnd;
%???????[eigvector?eigvalue]?=?NPE（options?fea）;
%???????Y?=?fea*eigvector;
%?
%?
%
%?See?also?LPP?LGE
%
%Reference:
%
%???Xiaofei?He?Deng?Cai?Shuicheng?Yan?and?Hong-Jiang
%???Zhang?“Neighborhood?Preserving?embedding“?Tenth?IEEE?International?
%???Conference?on?Computer?Vision?（ICCV‘2005）?2005
%
%???Sam?Roweis?&?Lawrence?Saul.?“Nonlinear?dimensionality?reduction?by?