MATLAB: Extract peaks and troughs from a curve

digital signal processingMATLAB

How to extract only peaks and troughs from a curve

Best Answer

If you want to identify the individual peaks and troughs, use islocalmax and islocalmin, or findpeaks on the positive and negative versions of your signal respectively:

[pks, pklocs] = findpeaks(s);
[troughs,trlocs] = findpeaks(-s);

where ‘s’ is youir signal vector.

Related Solutions

MATLAB: Correlation between two row matrices

Like that, each value of "a" is correlated to each value of "b", but applying the formula of the correlation, the correlation of two single numbers is NaN. To compute the correlation correctly, traspose the input vectors

result  = corr(a', b');

MATLAB: Plotting peaks and troughs of a large oscillating simulation data

One option, if you are using findpeaks, is to negate it and then plot the negative of the peaks.

Example —

t = linspace(0, 250*pi, 10000);                             % Create Data

s = sin(t) .* cos(t/50);                                    % Create Data
figure
plot(t, s)
[pospks,posidx] = findpeaks(s);                             % Positive Peaks
[negpks,negidx] = findpeaks(-s);                            % Negative Peaks
figure
plot(t(posidx), pospks)
hold on
plot(t(negidx), -negpks)
hold off

Best Answer

Related Solutions

MATLAB: Correlation between two row matrices

MATLAB: Plotting peaks and troughs of a large oscillating simulation data

Related Question