Improved performance of seperators function.

AlgebraicJulia · Nov 17, 2024 · 9fe79bc · 9fe79bc
1 parent 41e6a4e
commit 9fe79bc
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Showing 2 changed files with 10 additions and 56 deletions.
diff --git a/src/junction_trees/supernode_trees.jl b/src/junction_trees/supernode_trees.jl
@@ -52,36 +52,6 @@ function SupernodeTree(etree::EliminationTree, stype::SupernodeType=DEFAULT_SUPE
 end
 
 
-# Construct an elimination graph.
-function eliminationgraph(stree::SupernodeTree)
-    graph = deepcopy(stree.graph)
-    n = length(stree.tree)
-
-    for i in 1:n - 1
-        for u in supernode(stree, i)[1:end - 1]
-            v = u + 1
-
-            for w in outneighbors(graph, u)
-                if v < w
-                    add_edge!(graph, v, w)
-                end
-            end
-        end
-
-        u = last(supernode(stree, i))
-        v = first(supernode(stree, parentindex(stree.tree, i)))
-
-        for w in outneighbors(graph, u)
-            if v < w
-                add_edge!(graph, v, w)
-            end
-        end
-    end
-
-    graph
-end
-
-
 # Compute the width of a supernodal elimination tree.
 function width(stree::SupernodeTree)
     maximum(stree.degree[stree.representative])
@@ -99,45 +69,29 @@ end
 # Compute the (unsorted) seperators of every node in T.
 function seperators(stree::SupernodeTree)
     n = length(stree.tree)
-    seperator = Vector{Vector{Int}}(undef, n)
-    graph = eliminationgraph(stree)
-
-    for i in 1:n
-        clique = collect(outneighbors(graph, stree.representative[i]))
-        filter!(j -> stree.ancestor[i] <= j, clique)
-        seperator[i] = clique
-    end
-
-    seperator
-end
-
-
-# Compute the (unsorted) seperators of every node in T.
-function _seperators(stree::SupernodeTree)
-    n = length(stree.tree)
-    seperator = Vector{SparseIntSet}(undef, n)
+    seperator = Vector{Set{Int}}(undef, n)
 
     for i in 1:n - 1
-        seperator[i] = SparseIntSet(stree.ancestor[i])
-    end
+        seperator[i] = Set(stree.ancestor[i])
 
-    seperator[n] = SparseIntSet()
-
-    for i in 1:n - 1
         for v in outneighbors(stree.graph, stree.representative[i])
             if stree.ancestor[i] < v
                 push!(seperator[i], v)
             end
         end
+    end
 
+    for i in 1:n - 2
         j = parentindex(stree.tree, i)
 
         for v in seperator[i]
             if stree.ancestor[j] < v
                 push!(seperator[j], v)
             end
         end
+
     end
 
-    map(collect, seperator)
+    seperator[n] = Set()
+    seperator
 end
diff --git a/test/JunctionTrees.jl b/test/JunctionTrees.jl
@@ -114,7 +114,7 @@ stree = SupernodeTree(graph, order, Node())
     [17], # q
 ]
 
-@test map(sort, seperators(stree)) == [
+@test map(sort ∘ collect, seperators(stree)) == [
     [2, 9, 10],       # h i o
     [9, 10],          # i o
     [9, 16],          # i p
@@ -194,7 +194,7 @@ stree = SupernodeTree(graph, order, Maximal())
     [13, 14, 15, 16, 17], # l m n p q
 ]
 
-@test map(sort, seperators(stree)) == [
+@test map(sort ∘ collect, seperators(stree)) == [
     [9, 10],      # i o
     [9, 16],      # i p
     [6, 7],       # c d
@@ -277,7 +277,7 @@ stree = SupernodeTree(graph, order, Fundamental())
     [16, 17], # p q
 ]
 
-@test map(sort, seperators(stree)) == [
+@test map(sort ∘ collect, seperators(stree)) == [
     [9, 10],          # i o
     [9, 16],          # i p
     [6, 7],           # c d