Volterra

说明：  三角形网格上的线性有限元方法求解Helmholtz问题，多项式重构以及Richardson外推(solve the Helmholtz equation with robin boundary condition on triangulation mesh, PPR and Richardson extrapolation)

提供函数能进行1维2维的FFT，输入输出的序列长度应为2的整数次方倍(Provides functions can be one-dimensional two-dimensional FFT, sequence length input and output should be an integer power of 2 times)

说明：  利用有限差分法求解雷诺方程，进而可以求解气体静压轴承的特性(The Reynolds equation is solved by the finite difference method, and the characteristics of aerostatic bearing can be solved.)

可进行最小二乘法线性拟合输出，包含源代码及生成后的程序(Least-squares linear fit can be output)

用C语言编写的Fluent UDF实例，包含Adjust宏，profile宏等八个实例教程，快速上手(The UDF is for computational fluid dynamics software Fluent, it concludes the Profile.c,the Adjust.c)

利用ARIMA处理分析时间序列，计算数列相关性和数字特征并通过计算所得值进行一定范围的预测(ARIMA processing analysis time sequence, to calculate a number of columns and digital characterized by the calculated value for a certain range of the prediction)

book of document including test

test1.txt 第一列为时间t，0.001s为步长；第二列为系统的输入信号；第三列为系统的输出信号。 signal_analyzer.m首先将test1.txt 的数据读入workspace，然后进行FFT，分析出两信号的频率，输出对于输入的幅值衰减（db），输出对输入的相位差。(test1.txt the first time as t, 0.001s for the step the second as the system input signal the third as the system output signal. signal_analyzer.m first test1.txt data read workspace, and then proceed to FFT, analysis of the two signals in the frequency, the output for input amplitude attenuation (db), the output of the input phase difference.)

C++ SGP4 Satellite Library

小波包分析提取振动信号中的特征频率，微分方程组数值解方法，有循环检测，周期性检测。( Wavelet packet analysis to extract vibration signal characteristic frequency, Numerical solution of differential equations method, There are cycle detection, periodic testing.)