FFT_Original

An example of using a matrix object in order to pass values and complete a function.

格子玻尔兹曼模型DnQm系列模型中应用较为广泛的D2Q7模型源代码，用于模拟流体的流动。(The D2Q7 model source code of the the Lattice Boltzmann the model DnQm series model is widely used to simulate fluid flow.)

矩阵,复数自定义数据类型的C++实现,矩阵求逆采用牛顿法,(The matrix, complex number custom data type C realization, the matrix inverse uses the Newton method,)

求实对称矩阵的特征值特征向量，内有读入数据文件。(Realistic symmetric matrix eigenvalue eigenvector, there are read into the data file.)

C 语言，模拟流体相平衡过程，得到混合气体平衡态以后的工况参数(C language to simulate fluid phase equilibrium process, to obtain a mixed gas equilibrium after working parameters)

Orthogonal Polynomials Approximation 数值分析，计算正交基多项式的系数 (Given a function f and a set of m >0 distinct points . You are supposed to write a function to approximate f by an orthogonal polynomial using the exact function values at the given m points with a weight assigned to each point . The total error must be no larger than a given tolerance. Format of function int OPA( double (*f)(double t), int m, double x[], double w[], double c[], double*eps ) where the function pointer double (*f)(double t) defines the function f int m is the number of points double x[] contains points double w[] contains the values of a weight function at the given points x[] double c[] contains the coefficients of the approximation polynomial double*eps is passed into the function as the tolerance for the error, and is supposed to be returned as the value of error. The function OPA is supposed to return the degree of the approximation polynomial. Note: a constant Max_n is defined so that if the total error is still not small enough when n = Ma)

说明：  算法设计第三版，算法设计第三版，算法设计第三版，算法设计第三版(Algorithm Design Third Edition)

说明：  一维黎曼问题，一维问题，即激波管问题，是一个典型的一维可压缩无黏气体动力学问题，并有 解析解。对它采用二阶精度两步差分格式进行数值求解。(Riemann problem, One dimensional problem, the shock tube problem, is a typical one-dimensional compressible non viscous gas dynamic problem with analytic solutions. It is solved numerically by two order two step difference scheme.)

求解声学问题的边界元程序，给声学研究的人员很大启发(Solving the problem of acoustic boundary element program, to inspire great acoustic research staff)

这个程序分别用二分法，Newton法，弦截法，Newton下山法等算法求解非线性方程(this procedure were used dichotomy, Newton, String interception, Newton downhill law for solving nonlinear equations)