有较好的参考价值，Relief计算分类权重，结合PCA的尺度不变特征变换(SIFT)算法，使用混沌与分形分析的例程，FIR 底通和带通滤波器和IIR 底通和带通滤波器，是学习PCA特征提取的很好的学习资料。-There are good reference value, Relief computing classification weight, Combined with PCA scale invariant feature transform (SIFT) algorithm, Use Chaos and fractal analysis routines, Bottom-pass and band-pass FIR and IIR filter bottom pass and band-pass filter, Is a good learning materials to learn PCA feature extraction.