usermat

从旋转矩阵到四元数的转换，matlab代码。(From the rotation matrix to quaternion conversion, matlab code.)

非线性算法合集，包括牛顿拉夫逊法，Broyden拟牛顿法，弧长法，割线法。每种算法都包含有线性搜索迭代改进。(Nonlinear algorithm collection, including Newton Raphson, Broyden quasi-Newton method, arc-length method, secant method. Each contains a linear search algorithms for iterative improvement.)

模拟二维BZ反应扩散模型，方法是用显式EULER法求解模型的偏微分方程组(Simulated two-dimensional BZ reaction-diffusion model, the method is to use explicit EULER method for solving partial differential equations model)

基于abaqus umat的修正的M-C子程序，《ABAQUS在隧道与地下工程中的应用》-陈卫忠，版权归作者所有(Based on the modified MC abaqus umat subroutine, " ABAQUS in the tunnel and underground engineering" - Chen Weizhong, copyright of all)

经典的微扰法,包括各种各样的非线性动力学理论的研究方法及其基本原理(Classical perturbation method, including all kinds of nonlinear dynamics theory research methods and its basic principle)

随机调制信号下的模拟ppm，阐述了负荷预测的应用研究,是国外的成品模型。( Random ppm modulated analog signal under It describes the application of load forecasting, Foreign model is finished.)

采用凸优化的理论解决优化问题，使用python语言，采用pip安装即可(The convex optimization theory is used to solve the optimization problem. Python language is used and pip is installed)

以重力异常为例，对重力异常曲线进行圆滑和求导数。(This is a matlab code.It about smooth and derivative algorithm.)

基于蒙特卡罗算法的电力系统风险评估研究_李彦生。利用蒙特卡洛抽样和潮流计算方法计算电力系统可靠性(Based on the Monte Carlo algorithm for power system risk assessment studies _ Li Yansheng. Monte Carlo sampling and flow calculation method of the calculation of the power system reliability)

说明：  巴特沃斯、切比雪夫I和椭圆滤波器设计的源程序！非常难得！ 简洁的C语言编写(Butterworth, Chebyshev I and elliptic filter design of the source! Very rare! Concise C language)