Plot the result of findpeaks.

Dear all,

I captured human motion data of side-by-side walking in numerous data sets. The filtered data looks like that:

Now, I used the function findpeaks to find peaks and location of the filtered data and stored it in a struct.

for i = 1:numel (data)

[pks_1,locs_1] = findpeaks (data(i).filt_first_last_transposed (1,:)); % find peak and location

data(i).peaks_1 = pks_1; % store it into the struct 'data' with the field name peaks_1

data(i).locs_1 = locs_1; % see above

[pks_2,locs_2] = findpeaks (data(1).filt_first_last_transposed (2,:));

data(i).peaks_2 = pks_2;

data(i).locs_2 = locs_2;

end

I am struggling how to plot the filtered data including the identified pks. In doing so, I can inspect, if identified peaks are correct.

Any suggestions or an easier way to get results?

Regards, Jonas

[Image Analyst]

You forgot to attach your data. Make it easy for us to help you, not hard.

Is your second curve supposed to be data(1) and not data(i)?

Answer 1

[Image Analyst]

Perhaps this:

for i = 1:numel (data)
    % Find peaks for first column of the i'th data set.
    col1 = data(i).filt_first_last_transposed (1,:);
    [peakValues1, indexesOfPeaks1] = findpeaks(col1); % find peak and location
    data(i).peaks_1 = peakValues1; % store it into the struct 'data' with the field name peaks_1
    data(i).locs_1 = indexesOfPeaks1; % see above
    % Plot them
    hold off;
    plot(col1, 'b-', 'LineWidth', 2);
    hold on;
    plot(indexesOfPeaks1, peakValues1, 'cv', 'MarkerSize', 15, 'LineWidth', 2)
    % Find peaks for second column of the i'th data set.
    col2 = data(i).filt_first_last_transposed (2,:);
    [peakValues2, indexedOfPeaks2] = findpeaks(col2);
    data(i).peaks_2 = peakValues2;
    data(i).locs_2 = indexedOfPeaks2;
    % Plot them
    plot(col2, 'r-', 'LineWidth', 2);
    hold on;
    plot(indexesOfPeaks2, peakValues2, 'mv', 'MarkerSize', 15, 'LineWidth', 2)
end

If it doesn't work, attach data in a .mat file

save('answers.mat', 'data');

with the paperclip icon.

[Jonas Bender]

Dear Mr/Mrs,

thanks for your helpful advice. It works perfectly.

Jonas