Clear Filters
Clear Filters

How to determine concavity point?

9 views (last 30 days)
I have a bunch of data that when plotted look similar to this:
I want to know how I can use MATLAB to determine the corner or vertex or sometimes called concavity point (there are two in this plot that I have, one in the red data and one in the blue data)?

Accepted Answer

John D'Errico
John D'Errico on 8 May 2023
Edited: John D'Errico on 8 May 2023
You give no data, so I'll need to make some up for an example.
x = linspace(-30,30,500);
y = cumsum((atan(x - 10)/2 + 1));
plot(x,y)
grid on
So a simple enough curve. Can we locate the point where there is a change? As long as the stride between points is constant, then a tool like findchangepts might help.
ipt = findchangepts(y,'Stat','linear')
ipt = 331
[x(ipt),y(ipt)]
ans = 1×2
9.6794 88.9733
hold on
plot(x(ipt),y(ipt),'ro')

More Answers (0)

Tags

Products


Release

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!