concept_check

this is a program on matlab backpropagation of error.

利用MATLAB实现的一个简单的水声波束形成程序。实现波束入射角度的定位功能。(The use of MATLAB to achieve a simple acoustic beam-forming process. To achieve the positioning function of beam incident angle.)

已知一个LTI系统的差分方程为： y[n]-1.143*y[n-1]+0.4128*y[n-2]=0.0675*x[n]+0.1349*x[n-1]+0.0675*x[n-2] 初始条件y(-1)=1,y(-2)=2，输入x(n)=u(n)，计算系统的零输入响应 (known LTI system of a differential equation : y [n]-1.143* y [n-1] 0.4128* y [n-2] x = 0.0675* 0.1349 [n]* x [n-1] 0.0675* x [n-2] initial conditions y (1) = 1, y (2) = 2, input x (n) = u (n), we calculate the zero input response)

该函数用来计算时间序列的最大Lyapunov 指数 Wolf 方法 m: 嵌入维数 tau:时间延迟 data:时间序列 N:时间序列长度 P:时间序列的平均周期,选择演化相点距当前点的位置差，即若当前相点为I，则演化相点只能在|I－J|>P的相点中搜寻 lambda_1:返回最大lyapunov指数值 (This function is used to calculate the time series of the largest Lyapunov exponent Wolf method m: embedding dimension tau: time delay data: time series N: Time sequence length P: the average period of time series, the evolution of the current location of the point relative pitch poor, that is, if the current phase point is I, the evolution of the phase point only | I-J |> phase point P in search lambda_1: returns the maximum index value lyapunov)

说明：  MATLAB编程(第二版)是老师强烈推荐的，这个电子版是找了好久才找到的，很清晰，有目录。(MATLAB Programming (Second Edition) is the teacher strongly recommended that this electronic version is looking for a long time to find, very clear, there are directories.)

人脸识别的matlab pca源码，希望对大家有用处(face recognition Matlab pca source, we hope to be useful)

Its another MATLAB code...

在dq坐标系下建立异步电机，并进行启动仿真(In the dq system of asynchronous motor, and start the simulation)

基于FDTD与PML的连接边界条件的2维MRTD电磁正演散射模型。(Based on FDTD and PML connection boundary conditions is performed 2-D MRTD electromagnetic scattering model.)

输入信号为方波信号+高斯白噪声，方波信号基 频为1kHz，幅值为1，高斯白噪声方差为0.2， 均值为0，采样频率为20kHz。试用周期图法和 ARMA谱估计法(SVD-TLS)估计此信号的功率 谱，并分析比较其结果(The input signal is a square wave signal+ Gaussian white noise, square wave signal fundamental frequency 1kHz, amplitude is a Gaussian white noise variance is 0.2, the mean is 0, the sampling frequency is 20kHz. Try periodogram and ARMA spectral estimation method (SVD-TLS) estimate the power spectrum of this signal, and the analysis and comparison of the results)