Using the Signal Processing Toolbox function is significantly faster:
b = [0.2461, -0.0829, -0.0673, 0.0829, -0.1788];
a = [1.0000, -1.2841, 1.0272, -0.9329, 0.5279];
figure
[h,w] = freqz(b, a, 2^14);
[pks_vect_maxima2,locs_maxima3] = findpeaks(abs(h));
with the bode and findpeaks calls requiring about 1.7 seconds and the freqz and findpeaks calls requiring about 0.05 seconds when I tested them
You need to decide if the extrra coding required is worth the effort.
My test code:
options_bode = bodeoptions;
options_bode.MagUnits = 'abs';
G_filt_discrete = tf([0.2461, -0.0829, -0.0673, 0.0829, -0.1788], ...
[1.0000, -1.2841, 1.0272, -0.9329, 0.5279],1);
t1 = clock;
figure;
hold on;
bodemag(G_filt_discrete,'g',options_bode)
% Calculate local maxima/peaks value of transfer function
[mag,phase,wout] = bode(G_filt_discrete);
mag_vect = mag(:);
[pks_vect_maxima,locs_maxima] = findpeaks(mag_vect);
t2 = clock;
pkw = wout(locs_maxima)
b = [0.2461, -0.0829, -0.0673, 0.0829, -0.1788];
a = [1.0000, -1.2841, 1.0272, -0.9329, 0.5279];
figure
[h,w] = freqz(b, a, 2^14);
[pks_vect_maxima2,locs_maxima2] = findpeaks(abs(h));
t3 = clock
pkw2 = w(locs_maxima2)
et1 = etime(t2,t1)
et2 = etime(t3,t2)
