PCA如何来进行降维%%Thisscriptgeneratesandplots3Ddata,andperformsaprincipal%%componentanalysistodecorrelatethedata,andtoreducethe%%dimensionalityofthefeaturespace.%NotethatmatlabhasanoptimizedfunctiontoperformPCA:princomp()%However,inthisscriptweperformPCAmanuallybycalculatingthe%eigen