How to set EdgeWeights in SpatialGraphDistribution?

Question

I have a table of random geometric graphs

graphs = Table[
   RandomGraph[
    SpatialGraphDistribution[
     RandomVariate[PoissonDistribution[100]], 0.2]], {k, 1, 
    10}];

but I need the EdgeWeights of each graph to be the Euclidean distances between the vertices of the respective edge. At the moment they are all unity.

I tried using

graphs = SetProperty[#, 
     EdgeWeight -> EuclideanDistance @@@ EdgeList[#]] & /@ graphs;

but this obviously requires the vertex names to be position vectors. I also tried using

vertlist[graph_] := 
 VertexCoordinates /. AbsoluteOptions[graph, VertexCoordinates]

with another function which threads over the edges, but it seems inelegant...

Is there a simpler way?

Answer 1

You could use something like this:

rg = RandomGraph[SpatialGraphDistribution[RandomVariate[PoissonDistribution[100]], 0.2]]

dist = EuclideanDistance @@@ 
   Map[PropertyValue[{rg, #}, VertexCoordinates] &, EdgeList[rg], {2}];

SetProperty[
 rg,
 EdgeWeight -> dist
]

---

An alternative solution is

Graph[rg, 
 EdgeWeight -> {edge_ :> Apply[EuclideanDistance]@Map[PropertyValue[{rg, #}, VertexCoordinates] &]@edge}
]

What seems to be unavoidable is to first create the graph and assign it to a variable, then refer back to that variable. This is a general "problem" with the current design of the graph framework. It's a problem in the sense that doing this feels un-Mathematica-like.