对相干信号进行方位估计 TOELITZ_MUSIC

说明：  非线性振动教程，学习振动的学者们必须看的东西。(Nonlinear vibration tutorial, learning vibration scholars must look at things.)

变分模态分解的python版本，个人根据MATLAB版本译制而成(Python version of variational mode decomposition)

计算重力异常,只需要输入最大重力场模型的最大阶数以及重力场模型文件名在程序里设置经纬度范围和间隔即可得到重力异常(Gravity anomaly)

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)

3．1 线性方程组类设计 3．2 全选主元高斯消去法 3．3 全选主元高斯-约当消去法 3．4 复系数方程组的全选主元高斯消去法 3．5 复系数方程组的全选主元高斯-约当消去法 3．6 求解三对角线方程组的追赶法 3．7 一般带型方程组的求解 3．8 求解对称方程组的分解法 3．9 求解对称正定方程组的平方根法 3．10 求解大型稀疏方程组的全选主元高斯-约当消去法 3．11 求解托伯利兹方程组的列文逊方法 3．12 高斯-赛德尔迭代法 3．13 求解对称正定方程组的共轭梯度法 3．14 求解线性最小二乘问题的豪斯荷尔德变换法 3．15 求解线性最小二乘问题的广义逆法 3．16 病态方程组的求解 (3.1 system of linear equations class designs 3.2 to choose the principal element gaussian elimination 3.3 to elect principal element Gauss- when approximately the elimination 3.4 duplicate coefficient equation sets all choose the principal element gaussian elimination 3.5 duplicate coefficient equation sets to elect principal element Gauss- when approximately the elimination 3.6 solve three diagonal line equation sets to pursue the law 3.7 common belt equation set s solution 3.8 solution symmetrical equation set s resolution 3.9 solution symmetrical Zhengding equation set s square root method 3.10 solution large-scale sparse equation set to elect principal element Gauss- when approximately the elimination 3.11 solutions hold the Belize equation set s row article to abdicate House Holland who method 3.12 Gauss- the Seydell repetitive process 3.13 solution symmetrical Zhengding equation set s conjugate gradient method 3.14 solution linearity is smallest two rides the questionThe German m)

用SVD奇异值分解法和阻尼最小二乘算法解决地球物理反问题，程序比较简单易懂(Using SVD, singular value decomposition method and damped least-squares algorithm to solve geophysical inverse problem, the procedure is relatively simple to understand)

求解Riemann 问题精确解的Fortran程序(Exact solution of Riemann problem solving Fortran program)

最小二乘估值的SVD分解计算方法，本程序可将最小二乘估值问题转化为超定方程组的问题处理，且可用奇异值分解的方法计算最小二乘问题。(Least Squares Estimates of the SVD decomposition method, the valuation process can be transformed into squares overdetermined equations deal with the problem, and can be calculated singular value decomposition least squares problem.)

利用表达式求解和栈的只是，设计一个简易的数学题库， 可供小学生作业，并能给出分数。 要求：建立试题库文件，随机产生 n 个题目；题目涉及加减乘除，带括弧的混合运算；随时可以退出；保留历史分数，能回顾历史，给出与历史分数比较后的评价。(Use solving expressions and stack just design a simple math exam, students for the job, and can give a score. Requirements: Create test file, randomly generating n topics topics involving addition, subtraction with parentheses mixing operation ready to quit keep historical scores, can look back at history, and history is given uation scores after comparison.)

说明：  A numerical method for analysis of Korres2003