Good morning, I am not practical with colum expression. I am creating a column named “Number_2”. I want this column to be 1 or the value in cell above of the same column ("Number_2,-1) plus 1. I receive an error of missing column (the one that I am creating). I would expect the column to be recognize as it should be iterative. Is there any way to refer to row n-1 of the same column that I am creating? [image]

Hey there, right now it is not possible to refer to the column you are creating in the expression you are creating the column with. If I remember correctly in the release event it was mentioned it is on the roadmap to enable this in the new Expressions node in the future. [What’s New in KNIME Analytics Platform 5.3] A work around could be to add the column generically and then send it into a recursive loop that processes one row at a time…

Thanks for the explanation. I have used a workaround with group looping and it worked.

Note that the honorable @takbb found that CE does have some memory capability as well but might not be worth the effort to get it properly running if there’s an easier alternative. [image] Column Expressions have Long Memories too! Knowledge sharing OH… WELL THIS IS EMBARASSING! I was wrong about the capabilities of the Column Expressions node. The implication of this is: @iCFO will no longer be pointing people to my Java Snippets (although I always enjoyed the challenge! slight_smile ) @ArjenEX will be able to proclaim that Column Expressions can achieve whatever needs to be achieved rofl (unless of course you want to do it quickly, in which case… Java Snippets all the way… wink ) Some background… While researching/creatin…

wow I actually did not know that. Then let me rephrase - I guess officially this is not working, but there are ways to make it work if you know how to (and am OK to spend some extra effort).

Unknow colum in Column Expression

KNIME Analytics Platform

ArjenEX July 25, 2024, 12:51pm 4

Note that the honorable @takbb found that CE does have some memory capability as well but might not be worth the effort to get it properly running if there’s an easier alternative.