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what edges does add_boundary_penalties consider? #62
I'm glad to hear you're enjoying prioritizr. I think I understand your question, but please correct me if I'm missing something.
My impression is that the edge factor concept is used to assign a lower penalty to planning units along coastlines, so that solutions don't simply avoid planning units along coastlines. But, if you have an a priori reason to penalise the boundaries on certain planning units, then I would suggest manually specifying a matrix containing the "boundary penalties" using the
Let if me know if I've completely misunderstood your question or if that answer helps.
Great, so looks like I was understanding it correctly. Though it does sound like we might need to make a more complex boundary penalty matrix, perhaps, which is why I wanted to clarify things.
In our current case we have country borders that we need to be wary of, on some sides of our area. We also have many roads and railways we have to exclude and buffer within our area. And several existing PAs. The challenge comes as we only have area as cost, and presence-absence species, so connectivity specifications are a strong driver of the solutions. Without connectivity specifications the selections are too scattered. But we don't necessarily want these existing protected areas to 'seed' solutions around them (we end up getting mega protected areas).
So you can perhaps see how we might want to have the edge_factor applying also to edges created by the lock-out files as well as just the outside edges. I see now how easy that will be using the boundary_data argument, by specifying a pu - lockin/lockout layer :)
I guess that means what I'd recommend is for the eqn above to be noted in the reference, and that when it is called through the add_boundary_penalties this only applies to the planning unit file, rather than the planning unit - lockout file.