pi_phaseshift_grating

应用于高速碰撞的相关子程序，考虑了在高速碰撞中单元畸变的沙漏模型。。(Related subroutines used in high-speed collision, taking into account distortion in high speed crash in the hourglass model unit. .)

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)

基于蒙特卡罗模拟的概率潮流计算 基于蒙特卡罗模拟的概率潮流计算(Probabilistic power flow calculation based on Monte Carlo simulation to calculate the probability of the trend based on Monte Carlo simulation.)

薄板样条，一种很好的拟合曲线的方法。是最近比较常用的拟合方法。(thin plate spline is so nice fitting method. Features: (1) support arbitrary control points (2) allow regularization (3) estimate the warp parameters from corresponding pairs )

比特交织编码中的迭代解映射算法简化 复杂度比原算法降低(Bit interleaved coded mapping algorithm in the iterative solution simplifies complex than the original algorithm reduces)

说明：  短时傅里叶变换及短时傅里叶反变换的实现，简单可用(The realization of short-time Fourier transform and short-time Fourier inverse transform is simple and available)

Visual Basic 做的多功能计算器(Multi-function calculator with VB)

有限元分析源代码，能分析梁单元、膜单元、壳体单元等常用的有限元单元，并能计算模态、振型等(Finite element analysis of source code, capable of analyzing beam element, membrane element, shell element, such as commonly used finite element module, and the calculation mode, vibration mode, etc.)

基于多松弛因子的LB方法，运用C++编写方腔顶盖驱动流，计算方腔内流体的流场(Based on the LB method with multiple relaxation factors, the flow field of the square cavity top cover is written by C++, and the flow field of the fluid in the square cavity is calculated)

说明：  用fortran 70实现数值积分，并实例计算了三个函数，导出了积分值和误差(The numerical integration is realized by FORTRAN 70, and three functions are calculated with examples. The integral values and errors are derived.)