Find the increasing and decreasing point in array?

I have an array. Which is increasing. At one point it starts decreases.

This trend starts repeating many times in array. How to find that point in array where the trend starts?

[Image Analyst]

Define "trend". Is it the start of the first increasing part of a signal where you have many rising/falling sections? Maybe you can post a screenshot of your data plotted and point out the element that you say the "trend" starts at.

Answer 1

[Azzi Abdelmalek]

A=[1 2 3 2 1 4 5 6 7 5 2 0 4 5 6 10]
[peaks,idx]=findpeaks(A)

If you haven't a signal processing toolbox

A=[5 2 3 2 1 4 5 6 7 5 2 0 4 5 6 10]
d=sign([0 diff(A)]);
idx=strfind(d,[1,-1])

Answer 2

[Image Analyst]

Use the diff() function

differences = diff(yourArray);

increasing values will be positive and decreasing values will be negative.