Douglas_Peucker

己知一些离散的点，使用matlab利用最小二乘法拟合(Had a number of discrete points, with linear least squares fitting)

其基本思想是取B样条函数 为及基函数，在[a,b]中均匀划分区间，xi=a+ih,h=(b-a)/n,由于三次样条函数空间是n+3维的，所以把分点扩充到x-1,xn+1,则任意三次样条函数可用 线性组合来表示：(The basic idea is to take B-spline function and basis functions in [a, b] in the evenly divided intervals, xi = a+ ih, h = (ba)/n, because the cubic spline function is n+3 dimensional space , so the expansion points to the x-1, xn+1, then any cubic spline function can be expressed as a linear combination:)

天线组阵中相位差的递推最小二乘估计与滤波(Phase array antenna group recursive least squares estimation and filtering)

早期的圆柱绕流程序，用fortran语言编写，用来了解早期绕流流动的发展(flow around the cylinder)

计算流体力学讲义（基础篇） 任玉新（清华大学工程力学系 流体力学研究所）(The computational fluid dynamics notes (foundation article))

PCA算法程序设计步骤： 1、去均值 2、计算协方差矩阵及其特征值和特征向量 3、计算协方差矩阵的特征值大于阈值的个数 4、降序排列特征值 5、去掉较小的特征值 6、去掉较大的特征值(一般没有这一步） 7、合并选择的特征值 8、选择相应的特征值和特征向量 9、计算白化矩阵 10、提取主分量 (PCA algorithm programming steps: 1 to mean 2, calculation of covariance matrix and its eigenvalues and eigenvectors 3, the calculation of covariance matrix eigenvalues greater than the threshold number of 4, in descending order of eigenvalue 5, remove the smaller eigenvalue 6, remove the larger eigenvalue (usually not this step) 7, the combined choice of eigenvalues 8, select the appropriate eigenvalues and eigenvectors 9, computing whitening matrix 10, principal component extraction)

数值分析里面的：不动点迭代法、牛顿迭代法、共轭梯度法和最速下降法(Conjugate Gradient)

利用Mathematica实现数值分析，包括Gauss-Seidel迭代，Jacobi迭代法，SOR法，牛顿迭代法等(Mathematica is used to realize numerical analysis, including Gauss-Seidel iteration, Jacobi iteration, SOR method, Newton iteration method, etc.)

Dot Matrix 5 x 7 sample progmam , hope you enjoy

用于解决投入产出问题的RAS算法，已知矩阵的行和和列和，可以求出矩阵的具体值。(For the RAS algorithm to solve the problem of input and output. We know the rows and columns of the matrix,then the specific value of the matrix can be calculated.)