peaks

Find the peaks and troughs in a vector.

Description

A simple rugged script that finds the peaks and troughs of a signal, vector, or data points. The results are returned in two index vectors p and t.
Notice: Might drop end points or give two point where adjacent data have the same value.
Returns column-wise peak and through index vectors

• MATLAB release: MATLAB 5.2 (R10)

[Yuri Kotliarov]

1. Function PEAKS exists in R14.
2. vector has to be a column.
3. Will those commands do the same thing?
Xmax = find(diff(diff(X)<0)==1)+1;
Xmin = find(diff(diff(X)>0)==1)+1;

[Sergei Koptenko]

There are at least two entries in Matlab File Exchange- "Local min, max, nearest neighbour" from 2003-03-21 and "Find Peak Value" from 2003-12-10 that do exactly the same as this function.

[James J. Cai]

Xmax = find(diff(X,2)<0)==1)+1;
Xmin = find(diff(X,2)>0)==1)+1;

[John Walters]

Thanks, I don't have the latest Matlab version

[Gao Jianqiang]

In this article,can the author give me a example of the use of the peak.m.
Why can't I produce the same figure above?
Waiting for other friends help me?!
Thanks!

[Duane Hanselman]

No usable help text provided. It is unclear what the function does without testing it. Poor programming practices.

[ravs sam]

great code, could use comments!

[J W]

Is it possible to add a script/function to measure the absolute vertical distance between peaks and corresponding troughs?
Overall the function worked well identifying peaks and their horizontal location for me.

[hi ya]

this is rubbish, just use Diff() and don't bother downloading

[L J]

Works well, exactly what I was looking for. Thanks

[Ai Ve]

Check out EXTREME.M on this site, it is a great improvement, also for 2D!

[Dimitri Shvorob]

Outdated - see other comments.

[Viprali Bhatkar]

It is really helpful for finding peaks and troughs in any signal. Thank you!!

[Nikola Stanchev]

Excellent! The code is very helpful. Simple and genius.

[UMP]

Nagi Hatoum:
Can you give me an example of peak.m.How I can adapt peak.m into my file? This is the command:

%imported data from excel sheet
x=xlsread('Data_Test.xls','A4:A65536');
y=xlsread('Data_Test.xls','B4:B65536');
%signal plot
figure
plot(x,y);
title('Ripple current');
xlabel('Time');
ylabel('Voltage');
grid on

I really appreciate your help and also others response.