Problem with: <null> sometimes equals 0 and sometimes not

[AnSt]

Dear All,

This is my first post on the forum, please excuse me if it’s not perfect with the rules. I have a problem filtering data lists, could you please help?

I’m filtering the same list a couple of times in a specific sequence for specific values. I replace the found specific entries with a placeholder < null > to keep the data tree structure, since I’m also filtering other lists of the same structure but different data. The problem arises when I want to check an already filtered list (with some < null >s) for "0"s. Depending on the used component equality or equality with tollerance it either recognises < null > is not the same as “0” (as i want it) or it sess them as equal. See the figure below:

Figure 1

I would just use the equality without tollerance; however, it causes another trouble. My list is a list of point X-coordinates created in Voronoi tesselation and has entries “-0” (as in the screenshot no 2; it also has "0"s in it below, but not shown in the figure). The equality with tollerance filtration recognises those negative zeroes, but the filtration equality doesn’t…

Figure 2

I tried using < empty > instead of < null > when filtering the list, but it caused a red flag stating that it is text (!) and can’t be processed nummericaly.

I know there were some bug issues with the < null > already discussed in the forum (like here ), but I haven’t found a solution to the problem which I’ve encountered. Am I doing something wrong in the filtering or is it a bug? How to overcome this?

Thank you in advance!

[Bernd_Möller]

You can use the Null Item component to check for null items:

[AnSt]

Thank you Bernd Möller, I actually knew the command before and even tried (unsuccessfuly) using it before posting to solve the problem which I had encountered. But thanks to your suggestion I was encouraged to work with it again, since it seemed like ‘the community voice’ confirmed this component was the way for a workaround on the issue with “null = 0” or “null <> 0”.

I succeeded creating a bypass for this issue, though I still think there is somthing buggy here with the fact that “equal with tollerance” gives you the right answer for “-0” but with this odd “null = 0” behaviour, and on the other hand: “equal” omits “-0” but at the same time correctly omits nulls.