drilled-hole-PBG

时间积分算法在有限元动力学中的应用，可以计算结构的瞬态响应(This class implements a Newmark beta-gamma predictor-corrector time inte- gration scheme, with accelerations as primary unknowns. .A Newmark scheme assigns to the dofs the following 5 unknowns : - the displacement d and its predictor D - the velocity v and its predictor V - the acceletion a . Their expressions are calculated by the dofs in class Dof.)

高震荡积分程序，可以计算以cos函数为积分核的高震荡积分(High shock points program that can calculate the cos function as integral kernel of the high-shock points)

计算改进型SVSLMS算法，在初始收敛速度，时变系统分析能力等方面优于传统的LMS算法(Improved SVSLMS calculation algorithm, the initial convergence rate, time-varying systems analysis capability is superior to the traditional LMS algorithm)

矩量法实例 计算细导线的雷达散射截面，PPT资料(Instance of the method of moments to calculate the radar cross section of thin wire)

五点差分法(matlab)解椭圆型偏微分方程方程,分法,偏分,五点差分,椭圆型,偏微分方程(Five-point difference method (matlab) solutions of elliptic partial differential equations, sub-law, partial points, five-point difference, elliptic partial differential equations)

说明：  可以进行平面拟合，基于matlab语言，简单易懂(It can be used for plane fitting. It is simple and easy to understand based on MATLAB language.)

EnKF集合卡尔曼滤波代码，用于读写模式集合，包括两种扰动观测分析方案。(These files illustrate the model used for storing, reading and writing the ensemble of model states.)

说明：  计算两组向量之间的旋转矩阵。输入参数为在两个不同坐标系中的同名向量（模为1），返回参数是一个3X3的旋转矩阵。(The function of RM realize the rotation between two sets of vectors, whose magnitude are 1, defined in two different refrence frames. Input parameters are two sets of vectors r and b, return value is a rotaton matrix.)

Description 设a[0…n-1]是一个包含n个数的数组，若在i<j的情况下，有a[i]>a[j]，则称(i, j)为a数组的一个逆序对（inversion）。 比如 <2,3,8,6,1> 有5个逆序对。请采用类似“合并排序算法”的分治思路以O(nlogn)的效率来实现逆序对的统计。 一个n个元素序列的逆序对个数由三部分构成： （1）它的左半部分逆序对的个数，（2）加上右半部分逆序对的个数，（3）再加上左半部分元素大于右半部分元素的数量。 其中前两部分（1）和（2）由递归来实现。要保证算法最后效率O(nlogn)，第三部分（3）应该如何实现？ 此题请勿采用O(n^2)的简单枚举算法来实现。 并思考如下问题： （1）怎样的数组含有最多的逆序对？最多的又是多少个呢？ （2）插入排序的运行时间和数组中逆序对的个数有关系吗？什么关系？ 输入格式 第一行：n，表示接下来要输入n个元素，n不超过10000。 第二行：n个元素序列。 输出格式 逆序对的个数。 输入样例 5 2 3 8 6 1 输出样例 5(Set a[0... N-1] is a n array containing n numbers. If there is a [i] > a [j] i n the case of I < j, then (i, j) is a n inversion pair of a array. For example, <2,3,8,6,1> has five reverse pairs. Please use the idea of "merge sorting algorithm" to achieve the statistics of inverse pairs with O (nlogn) efficiency. The number of inverse pairs of a sequence of n elements consists of three parts: (1) The number of reverse pairs in the left half, (2) the number of reverse pairs in the right half, (3) the number of elements in the left half is greater than that in the right half. The first two parts (1) and (2) are implemented by recursion. To ensure the final efficiency of the algorithm O (nlogn), how should the third part (3) be implemented? Do not use O (n ^ 2) simple enumeration algorithm to solve this problem.)

This matlab code is a demo version of Bayesian linear regression.