Field_ampl_analy

这是SIR微分方程模型对初值问题的求解和作图(This is the SIR model differential equations to solve the problem of initial value and mapping)

对实际采集的舰船辐射噪声进行了demo谱分析，分别采用了窄带解调和宽带解调两种方式，得到了较清晰的轴频和叶频信息。(use narrow-band and broad-band methods to demodulate the ship-radiated noise which is actually colleted, there can see clear axle frequency and blade frequency in the demo spectrum.)

计算多材料单元平均应力应变,用于提取计算等效弹性模量 泊松系数(Calculate the average stress-strain of multi-material elements)

说明：  基于matlab实现的拉格朗日插值函数，牛顿插值函数代码。(Based on MATLAB Lagrange interpolation function, Newton interpolation function code)

说明：  用fortran 70实现数值积分，并实例计算了三个函数，导出了积分值和误差(The numerical integration is realized by FORTRAN 70, and three functions are calculated with examples. The integral values and errors are derived.)

三次样条插值函数实现 运行后画出曲线图，并得到插值函数表达式。(spline3)

fortran最优化计算方法常用程序汇编 包括一维最优化部分、无约束优化部分、约束优化部分 0.618法，分数法、二次插值法、三次插值法 共轭梯度法、DFP变尺法（导数）、DFP变尺法（差分）、阻尼最小二乘法、鲍威尔法、模式搜索法、单纯形法 混合罚函数法（SUMT调用DFP）、混合罚函数法（SUMT调用鲍威尔法）、综合约束函数双下降法、可变容差法、复合形法、网格法、随机试验法、解线性规划的单纯形法(fortran optimization calculation method used to assemble Including one-dimensional optimization section, part of unconstrained optimization, constrained optimization part 0.618, fractional method, quadratic interpolation, cubic interpolation Conjugate gradient method, DFP becomes ruler Act (derivative), DFP variable scale method (differential), damped least squares method, Powell method, pattern search method, the simplex method Mixed penalty function method (SUMT call DFP), mixed penalty function method (SUMT call Powell Law), integrated dual descent constraint functions, variable tolerance method, the complex method, grid method, random test, solving linear programming simplex Method)

计算矩阵内空间任意两点之间或者两个矩阵之间的欧式距离的代码。(The space between any two points is calculated matrix code or Euclidean distance between the two matrices.)

FFT A计权 倍频程分析 三分之一倍频程分析(F F T A w eight o c tave a n al o n e t hird o ctave)

用一个N点复序列的FFT同时计算两个N点实序列离散傅里叶变换(With an N-point complex sequence of N-point FFT calculate two real sequences discrete Fourier transform)