% Length of signal t = (0:L-1)*T; % Time vector S = 0.7*sin(2*pi*50*t) + sin(2*pi*120*t); Y = fft(S); plot([0:L/2]*Fs/L,abs(Y(1:L/2+1))/(L/2)); %取半边谱,这里要求L是偶数 title('Single-Sided Amplitude Spectrum of X(t)') xlabel('f (Hz)') ylabel('...
When X is a matrix, the length of the columns are adjusted in the same manner. Y = fft(X,[],dim)and Y = fft(X,n,dim)applies the FFT operation across the dimension dim. FFT Examples A common use of Fourier transforms is to find the frequency components of a signal buried in a ...
FFTDataInput.signals.plotStyle=0; FFTDataInput.blockName=''; FFTDATAa = power_fftscope(FFTDataInput); %% 生成FFTDATA结构体 % 以下内容需要人为设定 FFTDATAa.input = 1; %% 输入变量数 FFTDATAa.signal = 1; %% 通道选择 FFTDATAa.startTime = t(1); %% 起始时刻,不可为0 FFTDATAa.cycles ...
(Hilbert Spectrum ) % f——信号的频率向量(Frequency vector of signal) % t——信号的时间向量(Time vector of signal) % imfinsf——每个imf的瞬时频率(instantaneous frequency of each imf) % imfinse——每个imf的瞬时能量(instantaneous energy of each imf) [m,n] = size(hs); l = size(imf,2...
functiondo_fft(x,Fs,L) FT=fft(x); P2 = abs(FT/L); P1 = P2(1:L/2+1); P1(2:end-1) = 2*P1(2:end-1); f = Fs*(0:(L/2))/L; %figure plot(f,P1) title('Single-Sided Amplitude Spectrum of x(n)') xlabel('f (Hz)') ...
plot(1000*t(1:50),X(1:50)) title('Signal Corrupted with Zero-Mean Random Noise') xlabel('t (milliseconds)') ylabel('X(t)') % Compute the Fourier transform of the signal. Y = fft(X); % Compute the two-sided spectrum P2. Then compute the single-sided spectrum P1 based on P2 ...
% Plot the pulse in the time domain. figure(); plot(t,X) title('Gaussian Pulse in Time Domain') xlabel('Time (t)') ylabel('X(t)') % To use the fft function to convert the signal to the frequency domain, % first identify a new input length that is the next power of 2 from...
plot(t, signal) title('Time-Domain signal'); %Take fourier transform fftSignal = fft(signal); %apply fftshift to put it in the form we are used to (see documentation) fftSignal2 = fftshift(fftSignal); %xdft = xdft(1:length(s)/2+1); ...
function F=fft_hust syms x; T=20; n=10; %谐波的阶数 t=0:0.01:80; %如果创建-1,+1的方波直接调用square即可 %50是50%占空比 f=max(7*square(pi*0.1*t,50),3);%创建方波最大值是1,最小值是0 plot(t,f); grid on; hold on; ...
plot(sfft_mag); % plot fft result 如果仔细观察,发现定点的值是50,而我们sin波形的正弦信号幅度是1啊。。这是matlab fft返回结果定义的问题,我们只需要除以用于fft运算的采样点个数的一半即可: fftpts=length(s); hpts=fftpts/2; % half of the number points in FFT ...