三维 近场－远场 变换 FDTD

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：  模糊控制的C语言实现，双输入单输出，采用查表法进行模糊推理，去模糊方法采用重心法，易于单片机实现(C language realization of fuzzy control, double input and single output, using look-up table method for fuzzy reasoning, using center of gravity method for deblurring, easy to realize by single chip computer)

分支界限费用矩阵的说明文档，非常实用,建议下载哦(Branch line cost matrix documentation, very practical, it is recommended to download Oh)

这是利用C++ 编的fft(This is the C series fft)

sap4源代码！by fortran 这是一个有限元计算的软件 可以完成平面，三维的计算功能(SAP4 source code! By FORTRAN This is a finite element software can be completed planar, 3D computing power)

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.)

求概率分布函数的参数方法 采用迭代法估计Beta分布的分布参数，(Estimation of distribution parameters of Beta distribution by iterative method)

共轭梯度法求解凸二次规划，代码由C语言开发，老外编写的程序，很值得一读。(Conjugate gradient method for solving convex quadratic programming, code generated by C language development, foreigners prepared program, it is worth reading.)

基于P-Q分解法的快速潮流计算,可用于实际系统(The fast power flow calculation based on P-Q decomposition method can be used in practical system.)

是一个基于Fortran语言计算 第一主应力 和 第三主应力 结构数值计算方便的代码(Fortran language is a calculation based on the first principal stress and the third principal stress code structure to facilitate numerical calculation)