PCA源程序，主元分析源程序，可以用于变量的特征提取(PCA source code, principal component analysis source, can be used for variable feature extraction)

一种特征提取方法：结合主元分析(PCA)和核主元分析（KPCA）的前馈神经网络（FNN）(A feature extraction method: the feedforward neural network (FNN) combined with principal component analysis (PCA) and kernel principal component analysis (KPCA))