max and min in one cycle
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Mohanned Al Gharawi
le 16 Mai 2018
Commenté : Mohanned Al Gharawi
le 16 Mai 2018
Hi everyone
I have a signal, I need to find max and min values for each cycle in this signal.
Let's say we have the signal A which has two cycles:
Signal=[0 -2 -3 -3.5 -3.25 -2.5 -1.75 -1 0 1 1.8 2.6 3.25 3.5 3.25 2.6 1.7 0 -2 -3 -3.5 -3.25 -2.5 -1.75 -1 0 1 1.8 2.6 3.25 3.5 3.25 2.6 1.7 0]
as shown in the attached picture.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/190584/image.png)
I should get for the first cycle -3.5 and 3.25 and the same values for the second cycles.
Thank you in advance
2 commentaires
Réponse acceptée
Image Analyst
le 16 Mai 2018
If you have the Image Processing Toolbox, you can do this:
props = regionprops(Signal < 0, Signal, 'MinIntensity');
minIntensities = [props.MinIntensity]
props = regionprops(Signal > 0, Signal, 'MaxIntensity');
maxIntensities = [props.MaxIntensity]
but I get 3.5 for the maxima. Why are you saying 3.25?
Plus de réponses (1)
Walter Roberson
le 16 Mai 2018
[maxpk, maxloc] = findpeaks(Signal);
[minpk, minloc] = findpeaks(-Signal);
extremevals = [maxpk.', -minpk.'];
extremlocs = [maxloc.', minloc.'];
>> extremevals
extremevals =
3.5 -3.5
3.5 -3.5
>> extremlocs
extremlocs =
14 4
31 21
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