New presolve check warning: more features are needed on previously feasible problem

[ninzyfb]

New presolve check warning: more features are needed on previously feasible problem

[jeffreyhanson]

Hi @ninzyfb,

Yeah, this warning is just saying that many of the planning units have no features present within them. In the worse case scenario, this could potentially mean that "important" planning units are not selected in the prioritization, simply because there isn't enough biodiversity data to identify. It can also cause strange patterns in the prioritizations (e.g. see #268, #205). So, this warning is designed to help people recognize when they might not have enough features to generate "biologically" meaningful results, but it could be false positive depending what the prioritization is meant to do (e.g. if you care about rare/endemic species, then it doesn't matter if most of the planning units have no features present within them). If your confident that you've got the correct or enough features for your conservation planning exercise, you can safely ignore this warning. In other words, this warning isn't about the mathematical feasibility of the optimization problem, it's more about ensuring the results are informative (sort out like fitting a statistical model with a low degrees of freedom). Does that help?

[ninzyfb]

HI jeff, ok great thank you for clarifying, i was worried as usually didnt get this warning but maybe it came with a package updated. It makes sense as my planning area may be slighlty too big considering the extent of the conservaiton features so maybe something to think about for the future.
Thanks!

[jeffreyhanson]

No worries! Ok sounds great.