krf--

PCA的步骤： 1 先将数据中心化； 2 求得的协方差矩阵； 3 求出协方差矩阵的特征值与特征向量； 4 将特征值与特征向量进行排序； 5 根据要降维的维数d’,求得要降维的投影方向； 6 求出降维后的数据； (PCA steps: 1 of the first data center 2 covariance matrix obtained 3 obtained covariance matrix eigenvalues and eigenvectors 4 eigenvalues and eigenvectors will be sorted 5 according to the dimension of dimension reduction d ' , seek to reduce the dimension projection direction 6, the data obtained after the dimensionality reduction )

天在维普下载了一篇SPIHT算法改进的论文，（耿兴云，《基于改进SPIHT的静态图像编码》，电脑知识与技术：学术交流-2007年5期），我根据该文提出的改进算法，用Matlab来实现，却发现改进算法的程序运行速度比原算法还要慢，希望有兴趣的朋友进来看看，评论一下原因。(Days in the VIP downloaded a SPIHT algorithm to improve the paper, (Gengxing Yun, " based on improved SPIHT still image coding," Computer Knowledge and Technology: 5-year academic exchange-2 007), in accordance with this paper the improved algorithm Matlab to achieve, but found that the improved algorithm runs faster than the original algorithm is also slow, hope to have interested friends come to see, comment on why.)

惠更斯-菲涅尔衍射计算，非常不错，简单易行。(Huygens- Fresnel diffraction calculations, very good, easy.)

最短路径寻优路径规划程序，很不错(Shortest path optimization path planning process, very good)

麻省理工大学matlab课件及课后习题，适合学习(MIT Matlab the courseware and Homework suitable learning)

HDB3码的MATLAB程序，经典，记得保留(HDB3 code MATLAB programs, classic, remember to retain)

一个使用数学方法生成波形声音文件的源代码，可以载入预置数学公式，保存8位和16位单声道声音文件，可以设置振幅、频率、持续、采样等参数，可以调整波形斜面，回声。 这个代码值得推荐！(The use of mathematical methods to generate a waveform sound files of source code, can load preset mathematical formula, save 8 and 16-bit mono sound files, you can set the amplitude, frequency, continuous, sampling and other parameters, you can adjust waveform slope, echo . It is recommended this code!)

QPSK modulation using a prbs data input

Matlab关于香农信道容量公式演示实验Matlab关于香农信道容量公式演示实验(Matlab on Shannon channel capacity formula Matlab demonstration experiment on the Shannon channel capacity formula Demonstration)

OPENDSS源代码，用于电力系统仿真，也可用于MATLAB调用,nevtestcase(OPENDSS source code, used in power system simulation, can also be used to invoke MATLAB, nevtestcase)