RungeKuttaMethod-DifferentialEquations

里查得森(Richardson)法解偏微分方程的程序。解的是定步长的抛物型偏微分方程： du/dx - a * d2u/dx2 = 0 在程序中可以更改 a 的值以实现不同系数的解。由于它是一种显式格式，解的结果不稳定 在Matlab7下面运行发现竟然有一些值达到十的几十次方,这是算法本身决定的。不是程序有错误(Richard Anderson (Richardson) Solving partial differential equations procedures. Solution is scheduled to step parabolic partial differential equation: du/dx- a* d2u/dx2 = 0 in the procedure can be changed in order to realize the value of a different coefficient of the solution. Because it is an explicit format, the result of instability in the solution of the following Matlab7 running even found some value reached ten dozens of parties, this is the decision algorithm itself. Not a procedural error)

本文详细介绍了16QAM调制方式的算法和理论(a good document for understand the theory and algorithm of 16QAM )

5 m-files 1:SQ.m : converts from s-domain to q-domain 2:ZQ.m : converts from z-domain to q-domain 3:sym2s : converts from symbolic to s-domain tf2str : Converts from Transfer function to string sym2str : converts from symbolic to string

plotangle函数是一个可以用来画两个向量夹角的函数.(plotangle function is a painting can be used to the angle between two vectors function.)

pid demostration for contionous time sysytem

连续读取多张图像同一坐标像素点的灰度值大小(Read multiple images the same continuous pixel coordinates of the size of the gray value)

add menu in matlab tools

脉冲编码调制（PCM，Pulse Code Modulation）是一种将模拟语音信号转换成数字信号的编码方式，从数学上来看，量化过程就是把一个连续幅度值的无限数集合映射成一个离散幅度值的有限数集合，编码就是用一组二进制数来表示这些映射后的有限数。 国际标准化的PCM采用折叠二进制码，符合长途电话质量。根据量化方法的不同，PCM 可分为均匀量化PCM 和对数PCM 两大类，对数PCM中，A律和μ律编码都已被定为国际标准。 本程序实现了A律、μ律以及均匀量化三种PCM，并带有GUI界面，方便使用。可以计算编码后的码率、运行时间以及最小均方误差。(Pulse Code Modulation (PCM, Pulse Code Modulation) is an analog voice signal into digital signal encoding, from the mathematical point of view, the process is to quantify the magnitude of the value of an infinite number of continuous mapping into a discrete set of the limited range of values number set, code is a set of binary digits, said after a limited number of these maps. By folding the International Standardization of PCM binary code, in line with long-distance telephone quality. According to the different quantitative methods, PCM can be divided into uniform quantization PCM PCM and the number of two categories, on the number of PCM, A law and μ-law code have been designated as international standards. A law implemented in this program, μ law and the uniform quantization of three PCM, with a GUI interface, easy to use. Encoded bit rate can be calculated, running time and minimum mean square error. )

MATLAB检测图像中的多个圆，并且给出此圆的坐标和半径。(detect circle)

Demo in Blind source separation with sound file