对偏微分方程进行差分计算

说明：  在图像中加入可视水印，用matlab仿真，实验证明保持了较好的图像质量(in adding visual image watermarking using Matlab simulation experiment to prove that maintaining a good image quality)

DistMesh giving a singular FEM matrix?(Hi Anyone here with some experience of using DistMesh in finite element code? I m solving the scalar Helmoltz equation in an annular region in 2D: rho_1 < rho < rho_2 where rho_1 is the radius of a Perfect Electric Conducting cylinder and rho_2 is where the mesh is truncated using an Absorbing Boundary condition. Now, I ve written code to mesh the region myself (by dividing the region into annular rings and picking a fixed number of points on each ring) and I ve written another program which uses DistMesh to mesh the region. I get a nice solution using my own meshing code but the FEM matrix becomes singular when I use DistMesh. This is the DistMesh Code I used: Circle with hole rABC=1.5 rCyl=0.5 fdstring=sprintf( ddiff(dcircle(p,0,0, f),dcircle(p,0,0, f)) ,rABC,rCyl) fd=inline(fdstring, p ) box=[-2,-2 2,2] [p,N]=distmesh2d(fd,@huniform,0.04,box,[]) I tried changing box and the 0.04 value (initial edge length). But every time, the matrix becomes sin)

说明：  《数字图像处理与机器视觉:Visual C++与Matlab实现》6 支持向量机,综合案例——基于PCA和SVM的人脸识别系统(&quot Digital image processing and machine vision: Visual C++ and Matlab to achieve&quot 6 support vector machines, comprehensive case- based on PCA and SVM for Face Recognition System)

直流电机的空载特性仿真程序，可以求电机的额定电动势(motor machine)

2D Convection code. It works fine, just download it and run.

UN PROGRAMM DE BRUSHLESS DC MOTOR IN M FILE PART 4

并行组合扩频系统程序，包括数据映射程序和数据逆映射程序(Parallel Combinatory Spread Spectrum system simulation)

PV system working very good

MATLAB工具箱函数，适合于凸优化计算，CVX，使用简单，应用广泛(MATLAB toolbox function, suitable for convex optimization, CVX, easy to use, widely used)

MATLB神经网络代码，创建一个向前的BP网络进行训练( network program, which has very detailed notes, very suitable for the general neural network and artificial intelligence for beginners)