pca

从旋转矩阵到四元数的转换，matlab代码。(From the rotation matrix to quaternion conversion, matlab code.)

求解非线性方程组 的同伦曲线法(Solving nonlinear equations homotopy curve method)

世界上开源的速度最快的FFT变换程序FFTW的说明文档，搜集了好久才找到，都是中文的，有助于对FFTW的使用。(Open source in the world s fastest FFTW FFT transform program documentation, gathered for a long time to find, are all in Chinese, help to the use of FFTW.)

c++编写的小波包算法，可以实现小波包分解与重构，速度较快(A wavelet packet implementation written in C++, does wavepacket decomposition and reconstruction quite efficiently)

奇异值能量差分谱计算，可用于信号降噪处理(Singular value of the energy difference spectrum calculation can be used for signal noise reduction)

有限元计算基本程序，为毕业论文时编写的局部渗流计算程序。(Finite element method the basic procedures for the thesis prepared by local seepage calculation procedures.)

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)

扩展年有限元的相关文献，内含7篇综述，完整概括扩展有限元的发展。做这个方面的可以看一看。(Extended Finite element of the relevant literature, containing 7 review, complete the development of finite element summed expansion. So this area can take a look.)

扩展有限元软件包,用于模拟连续介质裂纹的萌生与扩展(XFEM simulation code written in MATlab)

对于应用数学专业学习非线性混沌控制的学生非常有用，可以下载并尝试自己动手改变后半部分，就能应用于新系统中(For students applied mathematics learning nonlinear chaotic control is very useful, you can download and try yourself to change the second half, will be able to be applied to the new system)