TA的每日心情 | 开心
2023-6-2 15:15 |
|---|
签到天数: 1 天 [LV.1]初来乍到
|
建议在帮助中搜fft，其范例example就是很好的例子，直接看英文原文更详细。程序如下，) z# ~. p5 B; i% n- r% y
%%模拟创建需要观察的信号
/ S! `7 w7 j i1 s5 L: PFs = 1000; % Sampling frequency
6 L, V2 Q5 H" p6 l* `) S# GT = 1/Fs; % Sample time
" K. T" O; L5 z" N6 mL = 1000; % Length of signal, b# A2 G _5 n8 I* u5 U
t = (0P-1)*T; % Time vector
- N5 j5 b6 Q' s+ w% Sum of a 50 Hz sinusoid and a 120 Hz sinusoid* r" O) `3 H) ]: V9 m+ W
x = 0.7*sin(2*pi*50*t) + sin(2*pi*120*t);! q$ e) ?8 T3 A: Q2 |9 j6 H
%这里改成加个cos的就是你想要的了 幅度相位平率组合自己设置吧3 @: @. I e/ q5 z3 E& O) [
y = x + 2*randn(size(t)); % Sinusoids plus noise
. V! b) I h% eplot(Fs*t(1:50),y(1:50))
0 ]7 Y, F; m5 T& s+ htitle('Signal Corrupted with Zero-Mean Random Noise')# T! z$ `$ P5 B! a9 _ F
xlabel('time (milliseconds)')- |0 ~* ` E6 ?) @; {
%%fft观察信号的频谱图
2 f3 Q9 e8 W) I5 k/ H# F' B4 RNFFT = 2^nextpow2(L); % Next power of 2 from length of y
6 h0 j% U/ \% Y8 A oY = fft(y,NFFT)/L;
?9 r5 y3 r# G. H2 l. L7 K$ ^f = Fs/2*linspace(0,1,NFFT/2+1);" d5 N3 _9 t! [0 W \& T& m
% Plot single-sided amplitude spectrum.
8 a" [# K( }) J, _# dplot(f,2*abs(Y(1:NFFT/2+1)))
9 C+ k# {# X rtitle('Single-Sided Amplitude Spectrum of y(t)')
0 R+ M1 C* |/ \0 x+ rxlabel('Frequency (Hz)')
- I. U2 T! y: G; Y. o7 S" sylabel('|Y(f)|')7 L h( b: k& P% H
|
|
/1 
发表于 2022-8-30 11:20
收藏
淘帖
支持！
反对！