newton

模拟波动方程的有限元程序，计算波场快照，有程序说明！(Simulation of the wave equation, the finite element program, calculate the wave field snapshot, procedural instructions)

计算按频率抽取的基4快速傅里叶变换算法，与基2FFT相比，基4FFT的乘法量约减少25 。(Calculating frequency taken by fast Fourier transform algorithm base 4, compared with the base 2FFT the base 4FFT multiplication about 25 less.)

C语言实现多项式的最小二乘拟合，可用于在区间上对函数进行拟合(C language polynomial least squares fitting, can be used to fit the function on the interval)

说明：  VC实现，天文导航算法及实现 包括数据的获取、加工、处理、保存为文件(VC, astronomy, navigation algorithm and implementation including data acquisition, processing, handling, preservation of documents)

Fortran 95程序设计【彭国伦】第7章原代码，非常有学习价值！(Fortran 95 programming [Lun Peng-- Chapter 7 of the original code, the very value of learning!)

求解一维热传导方程，格式包括FTCS、BTCS、CNCS三种差分格式(solve one dimension heat transfer equation. )

频率响应函数计算程序,通过输入结构的响应数据，识别结构的模态参数，matlab(frequency response function，)

关于走迷宫算法的实现程序，完全采用C++语言实现，可以运行(Maze algorithm program, fully C++ language, you can run)

基于Visual C++的地震信号处理程序源代码，包括常用的FFT和Hilbert变换代码。(Visual C++ based on the seismic signal processing program source code, including the commonly used FFT and Hilbert transform code.)

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)