How to detect a peak from a graph

A part of my work need me to peak the peak from a graph of cyclic nature with time vs velocity. I tried to use treshold and and others options. to locate the maximum peak but could also include the local maximums . Is there anyway of picking the maximum value? such as sliding window ?

Answer 1

[Azzi Abdelmalek]

Use findpeaks function

[Ede gerlderlands]

I did use that and it also includes the local maximums which are not my needs.

[Image Analyst]

But you accepted this answer?

Answer 2

[Image Analyst]

For local peaks I'd use findpeaks() in the Signal Processing Toolbox, or imregionalmax() in the Image Processing Toolbox. For a global peak, simply use the max function

[maxValue, indexOfMax] = max(yourSignal);

[Ede gerlderlands]

This gives me the global max and is single value. My graph has a cyclic characteristics with many peaks and troughs. What I want is those peaks excluding the local maximums . If I explained it correctly. Tnx

[Image Analyst]

Well now I have no idea if you want all the local peaks or not. How many peaks do you want? One or multiple? I think it's time for you to post an image of your data with arrows pointing to the peak(s) on the signal that you want to detect. Try http://snag.gy or http://tinypic.com.

[Ede gerlderlands]

Ok thank you I have already done it with your above answer

[Image Analyst]

You're welcome. Glad I could help.

Answer 3

[pramod kumar]

even i am also working on to find the peak of the signal i have tried inbuilt function [peak_value, peak_location] = findpeaks(Tx1Rx_1100mm_3plates);

[Image Analyst]

After reading this: http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer, post your own question, along with screenshot of your signal, and code (including data) that we can copy and paste to reproduce your situation.

Answer 4

[Chinnaiah Golla]

If you simply want to obtain the maximum(Peak) value of signal by excluding the local maximas, you can use the max function.

max_val=max(signal);