Trees are typed as unrooted but have a root node

[hlapp]

There are tress (for example TB2_Tr1022) that are rdf:type cdao:unrooted tree, but then there is a root node annotation.

[bendmorris]

I think this is the case for all trees. They're all unrooted and they all have root nodes. (Perhaps this is a larger issue - many phylogenetic formats don't distinguish between rooted or unrooted trees, so I've just been assuming unrooted.)

Is there an appropriate CDAO annotation for the first node in an unrooted tree? It's not the root, so what is it?

[bendmorris]

In recent discussions, it was agreed that it would be preferable to have a "pseudo-root" concept in CDAO for unrooted trees, but such a concept doesn't yet exist. At the moment, there's not a solution that's clearly superior to mine, so for now this will go unchanged.

[hlapp]

@bendmorris would you mind posting a request to the cdao-discuss list for adding such a property - briefly describe use-case, i.e., why is this needed, why among the existing properties there isn't a good fit, and if you have a suggested label for the property, add that too.