low_high

draw a circle from given informations

DFT进行频谱分析时的三种现象 1、混叠：对连续信号采样，要求连续信号是带限的，采样频率要足够高。Fs应满足Nyquist采样定理才不产生混叠。 采样前加低通滤波器防混叠 2、频谱泄漏：DFT对时域信号进行了截断（相当于采样信号乘了一个窗函数），时域的乘积相当于频域卷积，改变了原信号频谱。 改用其他窗函数（非矩形）改善泄漏。 3、栅栏现象：DFT 只给出了频谱在采样点上的取值，采样点间的频谱内容丢失。(DFT spectrum analysis of a three phenomena, aliasing : continuous signal sampling, requiring continuous signal is band-limited, the sampling frequency should be high enough. Fs meet the Nyquist Sampling Theorem would not have aliasing. Sampling former low-pass filter plus anti-aliasing 2, spectrum leakage : DFT right time domain signal a disconnect (equivalent to a sampling signal by a window function). time domain is equivalent to the product of frequency-domain convolution, changes in the spectrum of the original signal. Window functions to switch to other (non-rectangular) to improve leakage. 3, fenced phenomenon : DFT spectrum is given only at the sampling point value, sampling points of the spectrum as lost.)

说明：  关于管道泄漏泄漏信号的预处理，应用EEMD算法对真实泄漏信号进行仿真。(As for the preprocessing of pipeline leakage signal, EEMD algorithm is used to simulate the real leakage signal.)

lsqr.m 基于QR正交分解的最小二乘法......(lsqr.m QRLS............................)

灰色预测模型在Matlab的语言编程(基于GM（1，1）模型)(Gray model in Matlab programming language (based on GM (1,1) model))

抑制载波单边带simulink程序，进行频谱计算研究，分析信号特征。(Sideband suppressed carrier simulink program, Calculation of spectral analysis of the signal characteristics.)

应用傅里叶变换DFT，分析各种离散信号x(k)的频谱。离散周期信号可以展开成傅里叶级数，所以离散周期信号的频谱 是一个周期的周期性离散频谱，各谱线之间的间隔为 ，而且存在着谐波的关系。 (DFT application of the Fourier transform, analyze discrete signal x (k) of the spectrum. Discrete signal cycle can begin as Fourier series, the discrete signal spectrum is a cyclical cycle of discrete spectrum, the line between the interval, but there is a harmonic relationship.)

说明：  牛顿均差插值公式，使用各阶均差，比拉格朗日插值计算量省(Newton interpolation formula are poor, the use of the bands are worse than the Lagrange interpolation calculation of the volume of the province)

Matlab详细编程，各种ICA工具，各种介绍，欢迎下载，，，，(Matlab programming, wavelet decomposition are introduced, and the ICA... Welcome to download )

介绍了F16的动态方程，并给出了其simulink实现方式和控制算法。(Introduce the dynamic model of F16 and give its simulink model and control algorithm.)