MATLAB: How to measure maximum frequency component present in the recorded EEG signal so that I can use right filter ahead

denoising eeg signalmaximum frequency measurement

I am working on a single channel EEG dataset but not able to apply hamming window based Low Pass Filter to it for denoising. I am using DenoiseF = filter (Hd,m); {Hd= window function, m= dataset} but it says "??? Undefined function or method 'filter' for input arguments of type 'cell'." Also I need to know maximum frequency component in my signal so that I can decide whether I need to filter it or it is already in usable range. Someone please help. May be I am not using right codes in Matlab.

Best Answer

See the documentation on the fir1 (link) function. It uses a Hamming window by default.

Use the filtfilt function to do the actual filtering.

Related Solutions

MATLAB: How to design FIR lowpass filter with cutoff frequency, fc1 = 20 Hz and FIR bandpass filter with cutoff frequency fc2 = 10 Hz and fc3 = 35 Hz.

Déjà vu

how to design IIR highpass filter with cutoff frequency of 20Hz and FIR bandpass filter with cutoff frequency of 10Hz and 15Hz?

Make the appropriate changes to get the cascaded filter you want.

MATLAB: IIR Bandstop (Notch) Filter design

I have absolutely no idea what ‘2.01’, ‘2.02’ and ‘2.03’mean.

Here is a prototype bandstop filter design that you can change to produce the filter you want:

Fs = 900;                                                           % Sampling Frequency
Fn = Fs/2;                                                          % Nyquist Frequency
Wp = [48 52]/Fn;                                                    % Stopband Frequency (Normalised)
Ws = [0.9 1.1].*Wp;                                                 % Passband Frequency (Normalised)
Rp =  1;                                                            % Passband Ripple
Rs = 90;                                                            % Passband Ripple (Attenuation)
[n,Wp] = ellipord(Wp,Ws,Rp,Rs);                                     % Elliptic Order Calculation
[z,p,k] = ellip(n,Rp,Rs,Wp,'stop');                                 % Elliptic Filter Design: Zero-Pole-Gain 
[sos,g] = zp2sos(z,p,k);                                            % Second-Order Section For Stability
figure
freqz(sos, 2^18, Fs)                                                % Filter Bode Plot
set(subplot(2,1,1), 'XLim',[0 Fs/5])                                % Optional

set(subplot(2,1,2), 'XLim',[0 Fs/5])                                % Optional
% signal_filt = filtfilt(sos, g, signal);                             % Filter Signal

Un-comment the filtfilt line to filter your signal.

Best Answer

Related Solutions

MATLAB: How to design FIR lowpass filter with cutoff frequency, fc1 = 20 Hz and FIR bandpass filter with cutoff frequency fc2 = 10 Hz and fc3 = 35 Hz.

MATLAB: IIR Bandstop (Notch) Filter design

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