能量熵的计算，基于欧几里得距离的聚类分析，合成孔径雷达（SAR)目标成像仿真，LDPC码的完整的编译码，对于初学者具有参考意义。-Energy entropy calculation, Clustering analysis based on Euclidean distance, Synthetic Aperture Radar (SAR) imaging simulation target, Complete codec LDPC code, For beginners with a ref