Trying to Retrieve Profile View Graph Bottom Elevation

[zachri.jensen]

Ah sorry, I made a rookie mistake in my own example

Basically, the order of operations is not guaranteed in the above example. Even though the ProfileView.SetElevationRangeAutomatic is visually to the right of the ProfileView.MinElevation, that doesn’t mean that it gets executed afterwards. So sometimes the minimum elevation will be returned before setting automatic back to true, and sometimes it will be returned after it has already been set to true. The order is not guaranteed since they are in parallel branches. This is referred to as a race condition in computer science parlance. Whenever an output appears to be randomly different between runs, it’s an indication that there’s probably a race condition somewhere.

Anyway, so you just need to force Dynamo to execute things in a specific order. It’s a helpful technique in many other cases as well. You basically set up a simple “gate” that makes sure that certain things have to finish before passing along the output.

More info here:

Passthrough, how can i understand that?

It is simply just creating a list and then getting the first item in the list. So it could be rewritten as: List.FirstItem(passthrough,waitfor); Or you could even simplify it further and just do a code block with: [a,b][0]; It acts as a gate because Dynamo has to “collect” all of the items in the list before passing the contents on to the next node.