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高斯消元法、高斯列主元消元法解线性方程组。程序由本人独立完全独立完成。版权所有！(Gaussian elimination method out PCA Gaussian elimination method for solving linear equations. I am independent program consists entirely independently. All rights reserved!)

安德森的经典计算流体力学理论基础的学习用书。（英文版）(Anderson s classic theory of computational fluid dynamics-based learning book.)

单纯形法找初始可行解，上课留的作业，希望对别人有点用吧(Simplex method to find an initial feasible solution , hope it is useful for others.)

ABAQUS中用户材料子程序UMAT的开发主要解决两方面的问题：本构模型的建立和积分算法的选择。 本文主要研究非线性材料的UMAT实现方法，并重点研究其迭代算法部分，目前，用户材料子程序UMAT的迭代算法主要是常刚度法，常刚度法的优点在于算法原理较简单，程序编写较方便，缺点是当遇到复杂非线性材料时，其迭代次数较多，收敛速度也较慢，在这个情况下，本文采取的是一种迭代次数较少且收敛速度较快的切线刚度法，具体就是采用FORTRAN语言编制了基于Von-Mises模型的接口程序,并采用切线刚度算法，通过与ABAQUS自带本构关系计算的结果相比较，验证其正确性。(This paper studies the user subroutine UMAT of ABAQUS development methods, the use of FORTRAN language isotropic hardening material model of the interface program, studied the effects of such material is extremely elastic-plastic constitutive relation method. This article UMAT tightly around the secondary development of technology, the first principle of its interface detail, and then for the theory of nonlinear finite element incremental stiffness of the regular tangent stiffness method and the theory of algorithms to do an in-depth analysis of deduced a regular tangent stiffness and rigidity of the law of the specific expression of algorithm theory, and then the preparation of the two algorithms, respectively, of the UMAT program, and finally the establishment of a specific model checking, bringing with ABAQUS elasto-plastic constitutive relation of the calculated results compared to verify the correctness of the two.)

最小二乘法拟合进行n次多项式拟合，N用来控制拟合的次数，例如N=5时进行4次多项式拟合，还回的是拟合系数(Least squares fit polynomial n times, N is used to fit the number of control, e.g., N = 5 When quartic polynomial fitting, further back are fitting coefficients)

说明：  本程序是采用FDTD算法结合PML吸收边界，对对称三层平板光波导的模式场仿真(This program uses FDTD algorithm and PML absorbing boundary to simulate the mode field of symmetrical three-layer planar optical waveguide.)

单元刚度矩阵，用于计算三单元刚度矩阵，输出刚度矩阵(Element stiffness matrix is ​ ​ used to calculate the three-element stiffness matrix, the output stiffness matrix)

说明：  简单地实现了一、二、三维的K均值聚类，效果还不错，适合初步学习模式识别的同志们(Simple implementation of one, two, three - dimensional k-means clustering, the effect is not bad, it is suitable for the initial learning pattern recognition comrades)

外点罚函数方法，可以用来求解约束优化问题，也可以用来被调用在智能算法中(Point outside the penalty function can be used for solving constrained optimization problems, can also be used in intelligent algorithm called)

用于计算谱相关函数的时域平花FFT积累算法，可改参数，改输入信号类型(calculate spectral correlation function by using time smoothing FFT Accumulation Algorithm, you can change the parameters, and the type of input signal )