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，
. D! Y0 p" c j( ^' _1 [/ a%%模拟创建需要观察的信号4 `% i- `# ~0 |! @; u! s5 G$ H
Fs = 1000; % Sampling frequency
: Z8 |" ^# b; |( Y7 Z2 Z- uT = 1/Fs; % Sample time
8 d N! N9 ?6 L, \, O$ vL = 1000; % Length of signal
8 B2 p. _) j& a8 o7 Zt = (0P-1)*T; % Time vector
# M( F2 j6 ~& J+ m3 z8 I! w% Sum of a 50 Hz sinusoid and a 120 Hz sinusoid
+ y6 i+ m- O: M: Q6 [: F' F9 gx = 0.7*sin(2*pi*50*t) + sin(2*pi*120*t);
$ @, I @' P. F5 L8 n% g" Q/ ~# 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: T9 c: h% b# Q/ l4 i
y = x + 2*randn(size(t)); % Sinusoids plus noise
# L+ t* u, }7 `; U" `1 Aplot(Fs*t(1:50),y(1:50)); p% |9 O7 A7 }3 L5 T# n
title('Signal Corrupted with Zero-Mean Random Noise'), ]- Z E- F; |9 \0 g
xlabel('time (milliseconds)')0 F& P' d+ n, O9 \
%%fft观察信号的频谱图
0 N/ E7 [1 F2 _3 ^NFFT = 2^nextpow2(L); % Next power of 2 from length of y) I! F' a6 c, H
Y = fft(y,NFFT)/L;) h2 i8 Q. {5 D5 i
f = Fs/2*linspace(0,1,NFFT/2+1);4 f! P- V! p2 e2 F. A# `
% Plot single-sided amplitude spectrum.
. k* @9 E+ b4 [% g7 m8 Hplot(f,2*abs(Y(1:NFFT/2+1)))7 E, x4 J7 M2 E* A
title('Single-Sided Amplitude Spectrum of y(t)')3 J5 j. D# j! m R. f. a
xlabel('Frequency (Hz)')
$ D8 U6 {$ G6 m5 c- Xylabel('|Y(f)|')
) W U5 R) k2 u |
|
/1 
发表于 2022-8-30 11:20
收藏
淘帖
支持！
反对！