labi3

this file contains some m-files about calculating the fractional fourier transform

说明：  MATLAB 工具包 很不错的东西 (MATLAB tool kit is a good thing)

用MATLAB软件模拟瑞利衰落（仿真图形）(Using MATLAB software to simulate the Rayleigh fading)

Programm FNN calculates the embedding dimension f a time serie using the method of false nearest neighbors.

pid算法原理解释，对初入学习PID的同学有很大帮助(pid algorithm principle explanation for entering the learning of the students are very helpful PID)

image watermarking method

用matlab绘制线性调频信号的时域波形，同时对信号进行频谱分析，并考察采样频率以及信噪比对频谱分析的影响。(Matlab drawing with linear frequency modulation signal time-domain waveform, and spectral analysis of signals and the sampling frequency and signal to noise ratio study of the impact of spectrum analysis.)

ch3=softt(h3,thr1 clear clc I=imread( lena512.bmp ) imshow(I) I=double(I) II=I+30*randn(size(I)) figure imshow(II,[]) [a1,h1,v1,d1]=dwt2(II, sym8 ) [a2,h2,v2,d2]=dwt2(a1, sym8 ) [a3,h3,v3,d3]=dwt2(a2, sym8 ) sigma=median(abs(d1(:)))/0.6745 x=3*sigma thr1=x*2^(-1) thr2=x*2^(-0.5) thr3=x 小波图像去噪( ch3=softt(h3,thr1 clear clc I=imread( lena512.bmp ) imshow(I) I=double(I) II=I+30*randn(size(I)) figure imshow(II,[]) [a1,h1,v1,d1]=dwt2(II, sym8 ) [a2,h2,v2,d2]=dwt2(a1, sym8 ) [a3,h3,v3,d3]=dwt2(a2, sym8 ) sigma=median(abs(d1(:)))/0.6745 x=3*sigma thr1=x*2^(-1) thr2=x*2^(-0.5) thr3=x )

说明：  AM by matlab program

circiut battery charger used with inverter circiut