Unit1

计算流体动力学中湍流模型的源程序，代码十分宝贵(Computational fluid dynamics model of the source of turbulence, the code is very valuable)

LDL分解法，用于求解大型的线性方程组。此程序中最多能解100维的，速度还不错(LDL decomposition method for solving large-scale linear equations. This procedure can be up to 100 peacekeepers solutions, speed is not bad.)

编写求取下述矩阵四叉树四进制M码和十进制码程序，并将运算结果返回。 1, 1, 1, 1, 2, 2, 3, 3, 1, 1, 1, 1, 2, 2, 3, 3, 1, 1, 1, 1, 4, 4, 5, 5, 1, 1, 1, 1, 4, 4, 5, 5, 6, 6, 7, 8,13,13,14,14, 6, 6, 9,10,13,13,14,14, 11,11,12,12,15,16,19,19, 11,11,12,12,17,18,19,19 (Prepared to strike the following matrix quadtree quaternary M code decimal code and procedures, and the operation result returned. 1, 1, 1, 1, 2, 2, 3, 3, 1, 1, 1, 1, 2, 2, 3, 3, 1, 1, 1, 1, 4, 4, 5, 5, 1, 1, 1, 1, 4, 4, 5, 5, 6, 6, 7, 8,13,13,14,14, 6, 6, 9,10,13,13,14,14, 11, 11, 12,12,15,16,19,19, 11,11,12,12,17,18,19,19)

this is fft header file for fast fourier transform. with this file, you can compute frequency spectrum zero to tow pi.

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)

有限元计算开源库，可以用于计算动力、静力、磁场等等方面的计算(Finite element calculation open source library)

新建复数类进行复数运算，重载+、=+、*、/等运算符用于复数间的运算。(New complex class complex operation, overloading+ =+,*,/operator for computing the plural.)

用visual basic编译的布谷鸟算法的源代码,是一种很好地启发式智能算法。(Use visual basic compiler cuckoo algorithm source code, is a good heuristic intelligent algorithm. )

C语言版,机载SAR回波仿真程序，附有FFT和复数库，以及位图显示模块。本程序注释详解，对加深SAR的理解有很好的帮助(C language version, airborne SAR echo simulation program with FFT and complex database, as well as bitmap display module. Detailed notes of this procedure, for deepening the understanding of SAR has a good assist)

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)