说明：  lpp算法实现,Locality Preserving Projections局部保持投影算法 hexiaofei的论文
(lppLocality Preserving Projections (LPP) builds a graph incorporating neighborhood information of the data set. Using the notion of the Laplacian of the graph, we then compute a transformation matrix which maps the data points to a subspace. This linear transformation optimally preserves local neighborhood information in a certain sense. The representation map generated by the algorithm may be viewed as a linear discrete approximation to a continuous map that naturally arises from the geometry of the manifold .The new algorithm is interesting from a number of perspectives)