Swap row and column labels in triangular and hexagonal lattice constr…

…uctors (#38)

src/Graphs/generators/namedgraphs.jl

@@ -9,29 +9,29 @@ function hexagonal_lattice_graph(m::Int64, n::Int64; periodic=false)
     error("Periodic Hexagonal Lattice needs m > 1, n > 1 and n even")
   end
 
-  G = NamedGraph([(i, j) for i in cols for j in rows])
+  G = NamedGraph([(j, i) for i in cols for j in rows])
 
-  col_edges = [(i, j) => (i, j + 1) for i in cols for j in rows[1:(M + 1)]]
-  row_edges = [(i, j) => (i + 1, j) for i in cols[1:n] for j in rows if i % 2 == j % 2]
+  col_edges = [(j, i) => (j + 1, i) for i in cols for j in rows[1:(M + 1)]]
+  row_edges = [(j, i) => (j, i + 1) for i in cols[1:n] for j in rows if i % 2 == j % 2]
   add_edges!(G, col_edges)
   add_edges!(G, row_edges)
-  rem_vertex!(G, (1, M + 2))
-  rem_vertex!(G, (n + 1, (M + 1) * (n % 2) + 1))
+  rem_vertex!(G, (M + 2, 1))
+  rem_vertex!(G, ((M + 1) * (n % 2) + 1, n + 1))
 
   if periodic == true
     for i in cols[1:n]
-      G = merge_vertices(G, [(i, 1), (i, M + 1)])
+      G = merge_vertices(G, [(1, i), (M + 1, i)])
     end
 
     for i in cols[2:(n + 1)]
-      G = merge_vertices(G, [(i, 2), (i, M + 2)])
+      G = merge_vertices(G, [(2, i), (M + 2, i)])
     end
 
     for j in rows[2:M]
-      G = merge_vertices(G, [(1, j), (n + 1, j)])
+      G = merge_vertices(G, [(j, 1), (j, n + 1)])
     end
 
-    rem_vertex!(G, (n + 1, M + 1))
+    rem_vertex!(G, (M + 1, n + 1))
   end
 
   return G
@@ -48,27 +48,27 @@ function triangular_lattice_graph(m::Int64, n::Int64; periodic=false)
     error("Periodic Triangular Lattice needs m > 2, n > 4")
   end
 
-  G = NamedGraph([(i, j) for i in cols for j in rows])
+  G = NamedGraph([(j, i) for i in cols for j in rows])
 
-  grid_edges1 = [(i, j) => (i + 1, j) for j in rows for i in cols[1:N]]
-  grid_edges2 = [(i, j) => (i, j + 1) for j in rows[1:m] for i in cols]
+  grid_edges1 = [(j, i) => (j, i + 1) for j in rows for i in cols[1:N]]
+  grid_edges2 = [(j, i) => (j + 1, i) for j in rows[1:m] for i in cols]
   add_edges!(G, vcat(grid_edges1, grid_edges2))
 
-  diagonal_edges1 = [(i, j) => (i + 1, j + 1) for j in rows[2:2:m] for i in cols[1:N]]
-  diagonal_edges2 = [(i + 1, j) => (i, j + 1) for j in rows[1:2:m] for i in cols[1:N]]
+  diagonal_edges1 = [(j, i) => (j + 1, i + 1) for j in rows[2:2:m] for i in cols[1:N]]
+  diagonal_edges2 = [(j, i + 1) => (j + 1, i) for j in rows[1:2:m] for i in cols[1:N]]
   add_edges!(G, vcat(diagonal_edges1, diagonal_edges2))
 
   if periodic == true
     for i in cols
-      G = merge_vertices(G, [(i, 1), (i, m + 1)])
+      G = merge_vertices(G, [(1, i), (m + 1, i)])
     end
 
     for j in rows[1:m]
-      G = merge_vertices(G, [(1, j), (N + 1, j)])
+      G = merge_vertices(G, [(j, 1), (j, N + 1)])
     end
 
   elseif n % 2 == 1
-    rem_vertices!(G, [(N + 1, j) for j in rows[2:2:(m + 1)]])
+    rem_vertices!(G, [(j, N + 1) for j in rows[2:2:(m + 1)]])
   end
 
   return G

test/test_namedgraphgenerators.jl

@@ -25,6 +25,15 @@ using Random
   #Should just be 1 triangle
   @test is_path_graph(g)
 
+  g = hexagonal_lattice_graph(2, 1)
+  dims = maximum(vertices(g))
+  @test dims[1] > dims[2]
+
+  g = triangular_lattice_graph(2, 1)
+  @show g
+  dims = maximum(vertices(g))
+  @test dims[1] > dims[2]
+
   #Check consistency with the output of triangular_lattice_graph(7,7) in networkx
   g = triangular_lattice_graph(7, 7)
   @test length(vertices(g)) == 36