air-age

本程序是用数学方程试计算出一个点在一条线上的垂线坐标，并判断出在线内外，是测量中用的程序！(The test procedure is used to calculate the mathematical equation of a line a point in the vertical coordinate, and determine the line outside, the procedure used to measure!)

样条插值算法的matlab代码，包括一次样条插值，二次样条插值和三次样条插值，可根据需要选择(Spline interpolation algorithm matlab code, including a spline interpolation, quadratic spline interpolation and cubic spline interpolation, can be selected)

四阶龙格库塔法解一阶二元微分方程 应用于数值计算(Fourth-order Runge-Kutta method for solving a class of binary differential equations for numerical calculation)

用谱方法计算流体力学一些流动现象的整体稳定性,MIMO OFDM matlab仿真,本程序的性能已经超过其他算法。( Spectral methods of computational fluid dynamics flow of some of the overall stability of the phenomenon, MIMO OFDM matlab simulation, This program has exceeded the performance of other algorithms.)

利用emd算法解决经验模式分解的一些存在的端点效应问题。 有效的解决了问题。(Using emd algorithm to solve some of the empirical mode decomposition end effects exist. Effective solution to the problem.)

说明：  LDL分解。作为矩阵方程数值解法最基础的矩阵分解算法，LDL算法可以高效分解对称矩阵。(LDL decomposition. Numerical Solution of matrix equation as the most basic matrix factorization algorithm, LDL decomposition algorithm can be efficient symmetric matrix.)

汽车油耗计算（C实现）对于家用经济型小轿车来说，统计油耗是经常做的一件事。本题目要求根据汽油单价、每次加油所用钱数，以及该次加的油所跑里程数计算出该车的百公里油耗，并进行保存，根据需要给出统计数据。(Vehicle fuel consumption calculation (C implementation) for the household economy cars, the fuel consumption statistics is often one of the things. The questions asked based on gasoline price, amount of money each fuel used, and the second oil added to calculate the mileage run car 100 km fuel consumption, and save, according to the need to give statistics.)

Wdisp，是基于建造结构计算软件pkpm的结果数据提取文件，方便使用，提取数据后，可用于绘制曲线。(Wdisp, is based on The construction structure calculations software pkpm the results of data extraction files, easy to use, extract data, can be used to draw the curve.)

离散数据生成tin的优秀代码，注释多，易于学习和移植(Discrete data generated tin excellent code, comments, easy to learn and transplantation)

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)