improve PI model

matlab工具箱 包括测试函数 可实现函数调用(matlab toolbox includes a function call test functions can be realized)

matlab 版本的LDPC码的译码工具包，很实用(LDPC decoding tollkit of MATLAB Version)

人脸识别的一种基本算法，非常简练，注释也很详细(face recongnition)

说明：  code for image subtraction

How the K-mean Cluster work Step 1. Begin with a decision the value of k = number of clusters Step 2. Put any initial partition that classifies the data into k clusters. You may assign the training samples randomly, or systematically as the following: Take the first k training sample as single-element clusters Assign each of the remaining (N-k) training sample to the cluster with the nearest centroid. After each assignment, recomputed the centroid of the gaining cluster. Step 3 . Take each sample in sequence and compute its distance from the centroid of each of the clusters. If a sample is not currently in the cluster with the closest centroid, switch this sample to that cluster and update the centroid of the cluster gaining the new sample and the cluster losing the sample. Step 4 . Repeat step 3 until convergence is achieved, that is until a pass through the training sample causes no new assignments. (How the K-mean Cluster workStep 1. Begin with a decision the value of k = number of clusters Step 2. Put any initial partition that classifies the data into k clusters. You may assign the training samples randomly, or systematically as the following: Take the first k training sample as single-element clusters Assign each of the remaining (Nk) training sample to the cluster with the nearest centroid. After each assignment, recomputed the centroid of the gaining cluster. Step 3. Take each sample in sequence and compute its distance from the centroid of each of the clusters. If a sample is not currently in the cluster with the closest centroid, switch this sample to that cluster and update the centroid of the cluster gaining the new sample and the cluster losing the sample. Step 4. Repeat step 3 until convergence is achieved, that is until a pass through the training sample causes no new assignments.)

说明：  PacketX解码例子Decode.rar(PacketX\Examples\Scripts\Decode.rar)

MATLAB最短路径，最基础的计算网络最短路径的算法 floyd - 最短路问题 Syntax: [d,path]=floyd(a,sp,ep) (MATLAB shortest path, the most basic computing network shortest path algorithm)

分别用矩形窗、汉宁窗、海明窗、三角窗和Blackman窗设计一 的线性相位带通滤波器，观察它们的3dB和20dB带宽，并比较五种窗的特点。(Respectively rectangular window, Hanning, Hamming window, triangular window and Blackman window design a linear phase bandpass filter, observe their 3dB and 20dB bandwidth and compare the characteristics of the five windows.)

matlab在振动信号处理中的应用源代码及pdf(Application of MATLAB in vibration signal processing source code and PDF)

说明：  implementation of an example in genetic algorithms