How to find n values before and after a maximum of an array

Hi, everybody, new to Matlab. I want to be able to locate the maximun peak which is known(always at 1) and to be able to extract the data right before and after this maximun peak(see example on figure). And this should be done even if the max-peak value changes along the x-as. Please help :(

[Mathieu NOE]

hello

use the "findpeaks" function to localise the peak signal position (index)

from this index value you can easily define a lower index = peak_index - 10 and an upper index = peak_index + 10

and generate an extract of your signal : signal_extract = signal(lower index : upper index)

good luck

[Coryn Melissa LLamoza Carabali]

Hi, thank you for your answer. Is 'signal' a function? it doesn't seem to work :(

Answer 1

[Ameer Hamza]

Something like this will work

x; % array of x-values
y; % array of y-values
[max_y, max_idx] = max(y);
x_max = x(max_idx);

interval = 0.02; % length of interval before and after peak
idx = (x_max-interval < x) & (x < x_max+interval);
x_interval = x(idx);
y_interval = y(idx);

x_interval and y_interval contain values in around the peak.

[Coryn Melissa LLamoza Carabali]

You are a Genius! it works. thank you so much

[Ameer Hamza]

I am glad to be of help! :)