SortPt - sorting z-coord - something went wrong?

Grasshopper
1

Hi all,

does anybody know why the SortPt does not sort the points according to their z-coordinate?
See point 0 to 3 in the following screenshot.

image

Shouldnt it be
0 3.0, 3.3, 19.25
1 3.0, 3.3, 22.35
2 3.0, 8.9, 19.25
3 3.0, 8.9, 22.35

Simplified gh file attached.

Thanks for your help and time.
Best Florian

181008_PP.gh (14.8 KB)

2

Because sorting priority is X, Y then Z

image
image1221×818 68.7 KB

It might be displaying as the same, but 2 has a smaller Y value, so it came first
i’m guessing there’s rounding involved somehow, I don’t have a solution for you, just an observation.

3

In this way you can sort points by seeing the Z value of the points.
sort

1 Like
4

That’s the not the issue, The issue is he wants to sort via XYZ but as you see the Z’s are incorrect, which like @victorlin said there is probably some floating point error somewhere. My guess is in the Y values where something like the part of the list which goes:

3.0,8.9,22.35
3.0,8.9,19.25

might actually be something like

3.0,8.899999999999999995,22.35
3.0,8.899999999999999998,19.25

Hence the Z appearing out of order.

5

Thanks evo! To know the reason is the first step on finding a solution.

6

Thanks mikity. I will try this one.

7

Solved the issue by using ‘round’ before sorting

image
image.png702×244 31.7 KB

Maybe there is a more elegant way, but its fine for the moment. Thanks to all!

1 Like
8

Ouch, I’m sorry if I made any confusion… I thought “3” supposed to be right after “0”… Yes now I see that he said “3” shuold be right after “1” .