boundary_partitionedges, fix copy(pg::partitionedgraph) (#51)

src/Graphs/partitionedgraphs/partitionedgraph.jl

@@ -94,6 +94,20 @@ function edges(pg::PartitionedGraph, partitionedges::Vector{<:PartitionEdge})
   return unique(reduce(vcat, [edges(pg, pe) for pe in partitionedges]))
 end
 
+function boundary_partitionedges(
+  pg::PartitionedGraph, partitionvertices::Vector{<:PartitionVertex}; kwargs...
+)
+  return PartitionEdge.(
+    boundary_edges(partitioned_graph(pg), parent.(partitionvertices); kwargs...)
+  )
+end
+
+function boundary_partitionedges(
+  pg::PartitionedGraph, partitionvertex::PartitionVertex; kwargs...
+)
+  return boundary_partitionedges(pg, [partitionvertex]; kwargs...)
+end
+
 function copy(pg::PartitionedGraph)
   return PartitionedGraph(
     copy(unpartitioned_graph(pg)),

test/test_partitionedgraph.jl

@@ -6,6 +6,7 @@ using NamedGraphs:
   forest_cover,
   PartitionEdge,
   PartitionVertex,
+  boundary_partitionedges,
   parent,
   default_root_vertex,
   triangular_lattice_graph,
@@ -43,6 +44,8 @@ using Graphs
   @test is_tree(partitioned_graph(pg))
   @test nv(pg) == nx * ny
   @test nv(partitioned_graph(pg)) == nx
+  pg_c = copy(pg)
+  @test pg_c == pg
 
   #Partition the whole thing into just 1 vertex
   pg = PartitionedGraph([i for i in 1:nx])
@@ -51,6 +54,8 @@ using Graphs
   @test nv(partitioned_graph(pg)) == nx
   @test ne(pg) == 0
   @test ne(partitioned_graph(pg)) == 0
+  pg_c = copy(pg)
+  @test pg_c == pg
 end
 
 @testset "Test Partitioned Graph Partition Edge and Vertex Finding" begin
@@ -67,11 +72,17 @@ end
   @test partitionvertex(pg, (1, 1, 1)) == partitionvertex(pg, (1, 1, nz))
   @test partitionvertex(pg, (2, 1, 1)) != partitionvertex(pg, (1, 1, nz))
 
-  @test partitionedge(pg, NamedEdge((1, 1, 1) => (2, 1, 1))) ==
-    partitionedge(pg, NamedEdge((1, 1, 2) => (2, 1, 2)))
-  inter_column_edges = NamedEdge.([(1, 1, i) => (2, 1, i) for i in 1:nz])
+  @test partitionedge(pg, (1, 1, 1) => (2, 1, 1)) ==
+    partitionedge(pg, (1, 1, 2) => (2, 1, 2))
+  inter_column_edges = [(1, 1, i) => (2, 1, i) for i in 1:nz]
   @test length(partitionedges(pg, inter_column_edges)) == 1
   @test length(partitionvertices(pg, [(1, 2, i) for i in 1:nz])) == 1
+
+  boundary_sizes = [length(boundary_partitionedges(pg, pv)) for pv in partitionvertices(pg)]
+  #Partitions into a square grid so each partition should have maximum 4 incoming edges and minimum 2
+  @test maximum(boundary_sizes) == 4
+  @test minimum(boundary_sizes) == 2
+  @test isempty(boundary_partitionedges(pg, partitionvertices(pg)))
 end
 
 @testset "Test Partitioned Graph Vertex/Edge Addition and Removal" begin