photonic_crystal_period

说明：  umat公式详细介绍，我也不知道够20字了mei(the introduction of umat in abaqus)

本例是研究断裂问题的ABAQUS 子程序代码，使用Fortran语言编辑，研究扩展有限元的同志们可以借鉴一下。(This example is the study of fracture problems ABAQUS subroutine code, Fortran language editing, extended finite element study comrades can learn it.)

说明：  数值分析实验1.明确插值多项式和分段插值多项式各自的优缺点； 编程实现拉格朗日插值算法，分析实验结果体会高次插值产生的龙格现象；(Experiments of numerical analysis 1. Define the advantages and disadvantages of interpolation polynomials and piecewise interpolation polynomials. The Lagrange interpolation algorithm is programmed, and the Runge phenomenon produced by high-order interpolation is analyzed.)

用麦克麦考方法求解一维burgers方程的matlab代码(By Mike McCaw method for solving one-dimensional burgers equation matlab code)

增广拉格朗日乘子方法求解RPCA问题的方法，得到矩阵的稀疏成分和低秩成分。(argumented lagrange multiplier method that can make matrix be decomposed to a sparse matrix and low-rank matrix.)

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)

说明：  三次样条插值的MATLAB程序（三弯矩方程）(Cubic Spline Interpolation MATLAB (3 Moment equation))

有限元法求解泊松方程，用matlab编写的计算程序(Finite element method for solving Poisson)

一个案例代码，用最小二乘支持向量机的，预测煤炭量(A case code, using the least squares support vector machine to predict the volume of coal)

该程序是利用GIvens变换进行矩阵的QR分解(The program uses GIvens transform to solve QR matrix.)