How to detect specified regions on the curve?

Hello, dear matlab users and programers.

I have a 2D data set temperature vs time, like in image attached. What I have to do is to create an algorithm that will detect when the curve is start to rolling down and when the data stops to change (horizontal part of the curve).

As an idea I am going to calculate tangent of the line between two data points (when tangent is <0 means that curve is rolling down and when tangent is aprox. = 0, than it is constant). Are there any more precise method to do this?

Thank you very much!

Answer 1

[Michael Dombrowski]

Have a look at findpeaks which can give you the maxima of your function. Otherwise, just use max() to get the global maximum. Taking the derivative should also work similarly. See this previous answer.

[Andrii Mishchenko]

Hi Michael! Thank you very much! I will try the function you mentioned and also will test derivative approach. Than I will compare both and make a decision which one is the best for my data type.