Is findpeaks same as local maxima?

Hello, I applied findpeaks to my signal and found out the local maximas. I read that it takes the local maxima by checking if the point is greater than the neighbours. But there is one more condition right? That the derivative must be a zero at that point? Is this also satisfied?

Answer 1

[Birdman]

Let's have a look at the simple example from documentation of findpeaks:

data=[25 8 15 5 6 10 10 3 1 20 7];
findpeaks(data)

When you see the marked points on the plot, none of them are differentiable since there are more than one tangent line that can be drawn at those points. Therefore:

That the derivative must be a zero at that point? Is this also satisfied?

No, it is not, as you can see.