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Max Peak Distance (findpeaks)

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Stefano Francavilla
Stefano Francavilla on 4 Oct 2017
Hi, I'm using the 'findpeaks' function and i want to insert a min and max limit to the distance between the peaks. In the function there is only the parameter 'MinPeakDistance' and i need the equivalent "maxpeakdistance" too. Any suggestions? Thanks
  1 Comment
Janak Thotakura
Janak Thotakura on 12 Oct 2017
Can you explain what exactly do you mean by 'maxpeakdistance' in finding peaks? An example would be helpful.

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Answers (2)

The Matlabinator
The Matlabinator on 14 Oct 2017
I'm wondering about this too. There's a 'MinPeakDistance' that rejects peaks which are located within some specified distance. Is there an equivalent for peaks located above some threshold value?

Stefano Francavilla
Stefano Francavilla on 14 Oct 2017
I wrote this code, it isn't elegant but I hope could be helpful.
%%1st step - Find a large amount of peaks with non-stringent constraints
x = zeros(N,1); % x-vector (what you want)
y = zeros(N,1); % y-vector (what you want)
minpeakheight = 0; % what you want (fairly small value)
minpeakdistance = 0; % what you want (fairly small value)
[peak_vals,peak_locs] = findpeaks(y,x,'MinPeakHeight',minpeakheight,'MinPeakDistance',minpeakdistance);
ref = 0; % reference (what you want)
mpd = ref*0.9; % min peak distance (what you want)
MPD = ref/0.9; % Max Peak Distance (what you want)
%%2nd step - Find 1st peak
[~,index] = max(peak_vals(peak_locs<peak_locs(1)+mpd)); % index of the 1st peak
new_peak_locs = peak_locs(index); % position of the 1st peak
new_peak_vals = peak_vals(index); % value of the 1st peak
%%3rd step - Find other peaks
while peak_locs(end)>new_peak_locs(end)+mpd
index = find(peak_locs>new_peak_locs(end)+mpd & peak_locs<new_peak_locs(end)+MPD);
[~,jj] = max(peak_vals(index));
new_peak_locs(end+1) = peak_locs(index(jj)); % peaks position vector
new_peak_vals(end+1) = peak_vals(index(jj)); % peaks value vector
end

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