As usual, that’s some very helpful stuff HS_Kim! 
that’s really appreciated.
I understand what the first definition is doing, and although it doesn’t identify all the identical nodes, it actually helped me to spot an issue with the geometry (I shouldn’t have any v.2.
Sorry I should have better defined what I mean by identical.
As per your second post, the number of elements connecting to the node’s not the only requirement, there’s also the angle of the members connecting to the node (in 3d).
I am struggling to understand what part of your second definition is doing.
You are evaluating the angle between vectors from the node to the adjacent nodes (see first snapshot below) & the plane deconstructed Xdirection vector?
Is this similar to flattening the lines connecting at each node on a plan and evaluating the angles on that plane?
How can I take into account the 3dimensional features of each node?
See example on the last snapshot below.
Several nodes are identified as ‘type7’ but most of them are not identical (as per the definition above).
I’m also not sure how you are using the mass addition, to combine angles and lengths?
