intersect

Author: CarloLucibello

src/GNNGraphs/GNNGraphs.jl

@@ -54,6 +54,9 @@ export add_nodes,
 include("generate.jl")
 export rand_graph
 
+include("operators.jl")
+# Base.intersect
+
 include("convert.jl")
 include("utils.jl")
 

src/GNNGraphs/convert.jl

@@ -5,9 +5,10 @@ function to_coo(coo::COO_T; dir=:out, num_nodes=nothing)
     num_nodes = isnothing(num_nodes) ? max(maximum(s), maximum(t)) : num_nodes 
     @assert isnothing(val) || length(val) == length(s)
     @assert length(s) == length(t)
-    @assert min(minimum(s), minimum(t)) >= 1 
-    @assert max(maximum(s), maximum(t)) <= num_nodes 
-
+    if !isempty(s)
+        @assert min(minimum(s), minimum(t)) >= 1 
+        @assert max(maximum(s), maximum(t)) <= num_nodes 
+    end
     num_edges = length(s)
     return coo, num_nodes, num_edges
 end

src/GNNGraphs/gnngraph.jl

@@ -150,6 +150,11 @@ function GNNGraph(data;
             ndata, edata, gdata)
 end
 
+function GNNGraph(n::T; graph_type=:coo, kws...) where {T<:Integer}
+    s, t = T[], T[] 
+    return GNNGraph(s, t; graph_type, num_nodes=n, kws...)
+end
+
 # COO convenience constructors
 GNNGraph(s::AbstractVector, t::AbstractVector, v = nothing; kws...) = GNNGraph((s, t, v); kws...)
 GNNGraph((s, t)::NTuple{2}; kws...) = GNNGraph((s, t, nothing); kws...)

src/GNNGraphs/operators.jl

@@ -0,0 +1,13 @@
+# 2 or more args graph operators
+function Base.intersect(g1::GNNGraph, g2::GNNGraph)
+    @assert g1.num_nodes == g2.num_nodes
+    @assert graph_type_symbol(g1) == graph_type_symbol(g2)
+    graph_type = graph_type_symbol(g1)
+    num_nodes = g1.num_nodes
+
+    idx1, _ = edge_encoding(edge_index(g1)..., num_nodes)
+    idx2, _ = edge_encoding(edge_index(g2)..., num_nodes)
+    idx = intersect(idx1, idx2)
+    s, t = edge_decoding(idx, num_nodes)
+    return GNNGraph(s, t; num_nodes, graph_type)
+end

src/GNNGraphs/query.jl

@@ -28,6 +28,10 @@ end
 
 Graphs.has_edge(g::GNNGraph{<:ADJMAT_T}, i::Integer, j::Integer) = g.graph[i,j] != 0
 
+graph_type_symbol(g::GNNGraph{<:COO_T}) = :coo 
+graph_type_symbol(g::GNNGraph{<:SPARSE_T}) = :sparse
+graph_type_symbol(g::GNNGraph{<:ADJMAT_T}) = :dense
+
 Graphs.nv(g::GNNGraph) = g.num_nodes
 Graphs.ne(g::GNNGraph) = g.num_edges
 Graphs.has_vertex(g::GNNGraph, i::Int) = 1 <= i <= g.num_nodes

test/GNNGraphs/operators.jl

@@ -0,0 +1,6 @@
+@testset "Operators" begin
+    @testset "intersect" begin
+        g = rand_graph(10, 20, graph_type=GRAPH_T)
+        @test intersect(g, g).num_edges == 20
+    end
+end

test/GNNGraphs/transform.jl

@@ -128,4 +128,16 @@
             @test sort_edge_index(edge_index(g2)) == sort_edge_index(edge_index(g))
         end
     end
+
+    @testset "negative_sample" begin
+        if GRAPH_T == :coo
+            n, m = 10,30
+            g = rand_graph(n, m, bidirected=true, graph_type=GRAPH_T)
+
+            # check bidirected=is_bidirected(g) default
+            gneg = negative_sample(g, num_neg_edges=20)
+            @test is_bidirected(gneg)
+            @test intersect(g, gneg).num_edges == 0
+        end
+    end
 end

test/GNNGraphs/utils.jl

@@ -14,6 +14,14 @@
         @test sdec == s
         @test tdec == t
 
+        n1, m1 = 10, 30
+        g = rand_graph(n1, m1)
+        s1, t1 = edge_index(g)
+        idx, maxid = GNNGraphs.edge_encoding(s1, t1, n1) 
+        sdec, tdec = GNNGraphs.edge_decoding(idx, n1) 
+        @test sdec == s1
+        @test tdec == t1
+
         # directed=false
         idx, maxid = GNNGraphs.edge_encoding(s, t, n, directed=false)
         @test maxid == n*(n+1)÷2
@@ -28,6 +36,17 @@
         @test sdec == snew
         @test tdec == tnew
 
-        g = rand_graph(10, 30, bidirected=true)
+        n1, m1 = 6, 8
+        g = rand_graph(n1, m1)
+        s1, t1 = edge_index(g)
+        idx, maxid = GNNGraphs.edge_encoding(s1, t1, n1, directed=false) 
+        sdec, tdec = GNNGraphs.edge_decoding(idx, n1, directed=false) 
+        mask = s1 .> t1
+        snew = copy(s1)
+        tnew = copy(t1)
+        snew[mask] .= t1[mask]
+        tnew[mask] .= s1[mask]
+        @test sdec == snew
+        @test tdec == tnew
     end
 end

test/runtests.jl

@@ -23,6 +23,7 @@ include("test_utils.jl")
 tests = [
     "GNNGraphs/gnngraph",
     "GNNGraphs/transform",
+    "GNNGraphs/operators",
     "GNNGraphs/generate",
     "GNNGraphs/query",
     "utils",