fs = 100; % sampling frequency
t = 0:(1/fs):(10-1/fs); % time vector
S = cos(2*pi*15*t);
n = length(S);
X = fft(S);
f = (0:n-1)*(fs/n); %frequency range
power = abs(X).^2/n; %power
plot(f,power)
平移零频分量,然后绘制以零为中心的功率。
Y = fftshift(X);
fshift = (-n/2:n/2-1)*(fs/n); % zero-centered frequency range
powershift = abs(Y).^2/n; % zero-centered power
plot(fshift,powershift)
fs = 100; % sampling frequency
t = 0:(1/fs):(10-1/fs); % time vector
S1 = cos(2*pi*15*t);
S2 = cos(2*pi*30*t);
n = length(S1);
A = [S1; S2];
X = fft(A,[],2);
f = (0:n-1)*(fs/n); % frequency range
power = abs(X).^2/n; % power
plot(f,power(1,:),f,power(2,:))
平移零频分量,然后绘制每个信号以零为中心的功率。
Y = fftshift(X,2);
fshift = (-n/2:n/2-1)*(fs/n); % zero-centered frequency range
powershift = abs(Y).^2/n; % zero-centered power
plot(fshift,powershift(1,:),fshift,powershift(2,:))
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