simplecalculator

实现UTM平面坐标系到经纬度的双向转换，是地理方面应用的好助手(UTM plane coordinate system to achieve two-way conversion of latitude and longitude, is a good helper geographic applications)

说明：  使用牛顿迭代法求解非线性方程组，程序简单易懂，初学者都能看明白。(Newton iterative method is used to solve the nonlinear equations. The program is simple and easy to understand for beginners.)

多项式的加减法运算，输入的多项式带有未知数x和数字(Polynomial addition and subtraction calculations)

最优解回溯法0-1问题，为了构造最优解，必须在算法中记录与当前最优值相应的当前最优解。(The optimal solution backtracking 0-1 must be recorded in the algorithm, in order to construct the optimal solution, corresponding to the current optimal value, the current optimal solution.)

数值计算的算法，采用c++实现，移植容易，一定能够用。(Data processing)

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.)

一维分数福利叶变换的程序及其调用程序，可以应用于二维变换，实现图像的分数傅里叶变换。(Scores of well-being of one-dimensional Fourier transform of the procedures and called procedures, can be applied to two-dimensional transformation, to achieve the image of the fractional Fourier transform.)

小波包分析提取振动信号中的特征频率，调试通过可以使用，自己编的5种调制信号。( Wavelet packet analysis to extract vibration signal characteristic frequency, Debugging can be used, Own five modulation signal.)

划分网格一个开源的库，有限元的算法，很好用(Meshing an open source library = for finite element)

数字信号处理FFT算法rfft.c，简单易懂。。(Digital signal processing FFT algorithm rfft,Straightforward..)