Matlab filter electical spikes in accelerometric data

Question

I have a dataset of accelerometric data that is affected by electical spikes.

I\'m looking for a good method to filter out or reduce these spikes as need to calcula

Answer 1

A moderator merged this question with this question - that's why it looks a little messy here. This answer considers additional issues in the second question!

The following is not an entirely clean solution, the code is adopted from my previous answer, but I added an exception for your case, so you don't need to delete values at the beginning and/or end of your data manually. It discards only these invalid values, that shouldn't cause problems.

Af = csvread(strcat('example_data_with_peak.txt'),5,0); 

% Thresholds
Tl = -0.04;
To = 0.04;

% initialisation
peaks = find( Af < Tl | Af > To);
counter = 0;

while ~isempty(peaks)
    peaks = find( Af < Tl | Af > To);
    try
        Af(peaks) = ( Af(peaks-1) + Af(peaks+1) ) / 2;
    catch
        if peaks(1) == 1
            Af(1) = 0;
        else
            Af(end) = 0;
        end
    end   
    counter=counter+1;
end

figure(2);
plot(Af)

For determining the threshold you could use somethink like this, but it's also quite brute-force:

thresh = 15*mean(abs(findpeaks(Af)));