code of notch filter

Can any one help me how I can do notch filter in matlab?

Answer 1

[Jan]

Isn't this a nice question for an internet search engine?

http://www.lmgtfy.com/?q=Matlab+notch+filter

Answer 2

[Honglei Chen]

There is an example in the documentation

http://www.mathworks.com/help/dsp/ref/iirnotch.html

Answer 3

[Kiran]

clc

clear all

close all;

load 231m

data1=(val(1,:));

% data=data1/200;

data=(data1-1024)/200;

EKG=data;

% D = load('Sara Cooper ecgNoise.mat');

% EKG = D.DD2; % Signal

L = length(EKG); % Signal Length (samples)

Fs = 300; % Sampling Frequency

Fn = Fs/2; % Nyquist Frequency

t = (0:L-1)/Fs; % Time Vector (sec)

figure(1)

plot(t, EKG)

grid

axis([0 3 ylim])

FTEKG = fft(EKG)/L; % Fourier Transform

Fv = linspace(0, 1, fix(L/2)+1)*Fn; % Frequency Vector

Iv = 1:length(Fv); % Index Vector

figure(2)

semilogy(Fv, abs(FTEKG(Iv))*2)

grid

axis([0 7.5 ylim])

Fs = 300; % Sampling Frequency (Hz)

Fn = Fs/2; % Nyquist Frequency

Wp = [1 100]/Fn; % Passband (Normalised)

Ws = [0.5 110]/Fn; % Stopband (Normalised)

Rp = 10; % Passband Ripple (dB)

Rs = 30; % Stopband Ripple (dB)

[n,Ws] = cheb2ord(Wp, Ws, Rp, Rs); % Chebyshev Type II Order

[b,a] = cheby2(n, Rs, Ws); % Transfer Function Coefficients

[sos,g] = tf2sos(b,a); % Second-Order-Section For Stability

EKG_F = filtfilt(sos, g, EKG);

figure(3)

plot(t, EKG_F)

grid

axis([0 3 ylim])

title('Star Strider’s Bandpass Filtered EKG')

xlabel('Time (sec)')

ylabel('Amplitude (mV?)')

[Sumit]

hello, i want design such filter for ECG signal which is in the .wav file. how i do this ?