nark4

说明：  用em算法估计高斯混合模型参数，matlab代码(Estimation of Gaussian mixture model parameters by EM algorithm)

自己写了一个二维Euler方程的间断有限元程序 上次发了一个三角形单元的程序 因为不是曲边单元 所以在圆柱后面容易形成涡 现在把程序改为曲边四边形单元了 没有涡出现 单元是8节点四边形单元 节点编号顺序是 1 5 2 6 3 7 4 8 也就是四个角点依次 是1 2 3 4 然后是边的中点编号 5 6 7 8. 时间推进采用 Runge-Kutta 方法 数值通量采用全局Lax-Friedrichs通量 仍然不能捕捉激波 因为没有做重构或者加人工粘性 等这个做出来了 再发一次。 程序没有进行优化 比如说内存的消耗没有优化 比如直边单元的边界积分仍然采 用了曲边的积分方法 增加了计算量 比如面积分、线积分都是采用的是Gauss- Legendre-Lobatto积分 积分精度会比一般的Gauss-Legendre积分精度低一阶 等 等问题。 二维的 纯属交流性质 就没有考虑这些问题 ^_^ 如果物面全部是直边 那么只要改变一个参数N 就可以获得不同的计算精度 且具 有谱精度 因为单元的节点是Gauss-Legendre-Lobatto积分点。 其实就是谱元法 （物面是曲边的情况我不清楚是不是也可以通过提高基函数的阶数 也就是增加N 来提高计算精度）(Wrote a two-dimensional Euler equations with discontinuous finite element program Last made ​ ​ a triangular element of the program, not curved edge unit is so easy to form a vortex in the cylinder behind the Program to curved edge quadrilateral element vortices appear Unit is the order of 8-node quadrilateral element node number is 15,263,748 which is the four corners of the points in turn Is 1234 and then the side of the midpoint of the number 5678. Time promote the use of Runge-Kutta method Numerical flux of the overall situation of Lax-Friedrichs, flux Still can not capture the shock wave did not do the reconstruction or artificial viscosity do it Zaifayici. The program is not optimized for example, memory consumption is not optimized such as straight-edge boundary integral of the unit is still mining Integral method to increase the amount of computation such as surface integral with a curved edge, the line integral using the Gauss- The Legendr)

说明：  四级四阶龙格库塔格式，求解微分方程的好算法。(Four fourth-order Runge-Kutta format, a good algorithm for solving differential equations.)

该文件是用matlab开发的图论分析工具箱， 里面有使用时的详细说明，pdf说明文档。 绝对实用对于图论的研究者(The document was developed with matlab graph theory analysis toolbox, which are used when a detailed explanation, pdf documentation. Absolutely useful for researchers in graph theory)

香农编码的C语言实现，VC++环境~~~~~~~~~~~~~~~~~~~~~~~~~(Shannon C-language coding, VC++ environment ~~~~~~~~~~~~~~~~~~~~~~~)

用追赶法来求解三对角线性方程组，解决数值分析问题，与大家共同学习。并且提供黄金分割法、高斯赛德尔迭代法求解数值分析问题(The catch-up method is used to solve tridiagonal linear equations, to solve numerical analysis problems, and to learn from you. The Golden Section Method and Gauss Seidel Iteration Method are also provided to solve numerical analysis problems.)

自制的计算器，可实现加减运算，清除，后退等功能(Homemade calculator, can realize the addition and subtraction, clear, back, etc)

有限元法求解泊松方程，用matlab编写的计算程序(Finite element method for solving Poisson)

信息是个很抽象的概念，本文介绍了熵的概念，并介绍计算方法(information is a very abstract concept, this paper introduces the concept of entropy, and the calculation method introduced)

说明：  matlab常用算法程序集主要用于解决插值、函数逼近、矩阵特征值计算、数值微分、数值积分、方程求根、非线性方程组求解、解线性方程组的直接法、解线性方程组的迭代法、随机数生成、特殊函数计算、常微分方程的初值等问题(Mainly solve interpolation, function approximation, matrix eigenvalue calculation, numerical differentiation, numerical integration, equation roots, nonlinear equations solving, direct methods for solving linear equations, iterative methods for solving linear equations, random number generation, special functions Calculation, initial value of ordinary differential equations, etc.)