Hi There,

I have got a list of y coordinates values in grasshopper, which I want to use the Expression (If command) to insert “A” in y coordinates list whenever one of the y coordinates values is bigger than its previous value plus 3.

So it basically means if Y(i+1)>Y(i)+3 then insert A

Here is a picture:

And here is the grasshopper File:

Question.gh (9.3 KB)