How do I calculate the coherence within a specific frequency range?

Hello,

I am calculating the wavelet transform coherence betweem two signals. I am trying to extract the average coherence between 0.01-1Hz. I have tried using the f output of the wcoherence() function however, I'm confused by this output becasure it is a matrix of complex numbers that are both positive and negative. In the plot, I can clearly see that there are values within this frequency fange however, the current approach I'm using returns NaN or the values increase linearly with the increasing frequency band which does not seem correct.

How do I extract the average coherence within this frequency range?

Here is the code I am currently using:

load('x') % load signal 1
load('y') % load signal 2
fs = 10; % 10 Hz sampling rate

[wtc, f, coi] = wcoherence(x, y,fs); % calculate the coherence between the signals

fbandStep = 0.05; % frequency step for defining the frequency bands to calculate average coherence

for k = 0.01:0.05:1-fbandStep
    % define upper and lower frequency bounds
    lowerFrequencyBound = k;
    upperFrequencyBound = k+fbandStep;
    
    % Find indices corresponding to the frequency range
    freqIndices = find(f_trial >= lower & f_trial <= upper);
    % Extract coherence values for the specific frequency range
    avgCoherence(k) = mean(wtc_trial(freqIndices));
    clear freqIndices
end

[Mathieu NOE]

hello

seems to me there is a bug in your code

[wtc, f, coi] = wcoherence(x, y,fs); % calculate the coherence between the signals

should be

[wtc, wcs, f, coi] = wcoherence(x, y,fs);

according to the doc , this is the right way :

[wcoh,wcs,f] = wcoherence(x,y,fs) 
[wcoh,wcs,f,coi] = wcoherence(x,y,fs)