假设你的信号是 8个点,采样频率是 100Hz。那么,该信号的频率是50Hz,那么频率轴每个间隔是 50/(8-1), 设为df 那么,频率轴是 0 df 2*df 3*df 4*df 也就是说,对于8个点的信号,你会得到频率间隔是 50/(8-1), 可以得到 8/2+1个频率点。也就是说,对于N个点的信...
% - f_sampling: the signal sampling frequency in Hz. % % Output: % - STFTcoef: Spectrogram. Column: frequency axis from -pi to pi. Row: time % axis. % % Check that f is 1D if length(size(f)) ~= 2 | (size(f,1)~=1 && size(f,2)~=1) error('The input signal must 1D....
1. matlab一维FFT function [X,freq]=MyFFTCentered(x,div) % to help plot two-sided spectrum with reference to laser omega(k) %===input=== % x: signal data % div: dt/T or dx/lambda %===output=== % X: center fft data % freq: the frequency axis N = length(x); Fs = 1/di...
%%使用fft实现周期图法%Input% signal -Signal vector 输入信号(行向量)% nsc -Number SeCtion 每个小分段的信号长度% nov -Number OverLap 重叠点数% fs -Frequency of Sample 采样率%Output% S - A matrix that each columisa FFTfortime of nsc% 如果nfft为偶数,则S的行数为(nfft/2+1),如果nfft为奇数...
function [X,freq]=centeredFFT(x,Fs) %this is a custom function that helps in plotting the two-sided spectrum %x is the signal that is to be transformed %Fs is the sampling rate N=length(x); %this part of the code generates that frequency axis ...
f=[0:binwidth:srate-binwidth]; % frequency scale goes from 0 to sample rate.Since we are counting from zero, we subtract off one binwidth to get the correct number of points plot(f,sfft_mag_scaled); % plot fft with frequency axis ...
Express the numerator and denominator as polynomial convolutions. Find the frequency response at 2001 points spanning the complete unit circle. clc;clear;close all; b0 = 0.05634; b1 = [1 1]; b2 = [1 -1.0166 1]; a1 = [1 -0.683]; ...
%虚部 Cn =(CnR.^2+CnI.^2).^(1/2); %幅值 fain =tand(CnI./CnR)/3; %相位⾓ fain =fain(1,48:54); %去除影响因素 figure stem(Range,CnR) %离散绘制 grid axis([-6,6,-2,2])title('实频谱')xlabel('Hz')ylabel('CnR')figure stem(Range,CnI,'Marker','none','LineWidth',3)
STFT2 = STFT1(1:nff/2+1,:);% Symmetric results of FFT STFT2(2:end-1,:) = 2*STFT2(2:end-1,:);% Add the value of the other half STFT3 = 20*log10(STFT2);% Turn sound pressure into dB level % Axis Generating fax = fs*(0:(nff/2))/nff;% Frequency axis setting ...
plot(freq,abs(fftshift_quot),'r-') grid on; xlabel('frequency') ylabel('amplitude') hold on; sigma=1.5; mu=20.48; fx=[exp(-((freq-mu).^2)/(2*sigma^2))]'; plot(freq,abs(fx),'b-') axis([0,40.94,0,50]) product=fx.*fftshift_quot; ...