EXTREMES (Z) - Plane mystery

https://grasshopperdocs.com/components/grasshoppercurve/extremes.html

I am trying to find the extremes of this curve in the XY plane… and failing miserably ( The docs say nothing about the requirements of the input curve having three dimensions

The curve has no Z value. its a 2D curve that sits ON THE XY plane, so I expect the XY plane to be the correct choice

1
u

2
j

3
y

To follow on from this thread…

How is this done?

It works as expected, I don’t know what do you expect. if you mean the curve ends, use End Points component.

I this what you mean?
curve extremes.gh (7.2 KB)
Y-extremes

Perfect. Thankyou )

What is going on here:

l

There should only be 4 intersections returned…

Extents 002.gh (9.1 KB)
I hope the curve stuck to this file

I don’t know, tolerance issue maybe. I opened the file in millimeter template with tolerance set to 0.001 and your gh file returns 4 extremes, as expected.

aaah of course. Thank you