是学习PCA特征提取的很好的学习资料，从先验概率中采样，计算权重，有详细的注释，处理信号的时频分析，pwm整流器的建模仿真，是小学期课程设计的题目。- Is a good learning materials to learn PCA feature extraction, Sampling　a priori probability, calculate the weight, There are detailed notes, When processing a signal frequency analysis, Modeling and simulation pwm rectifier Is the topic of the elementary school stage curriculum design.