// Copyright ©2014 The gonum Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package simple import ( "math" "sort" "testing" "gonum.org/v1/gonum/graph" "gonum.org/v1/gonum/graph/internal/ordered" ) var ( _ graph.Graph = (*UndirectedMatrix)(nil) _ graph.Directed = (*DirectedMatrix)(nil) ) func TestBasicDenseImpassable(t *testing.T) { dg := NewUndirectedMatrix(5, math.Inf(1), 0, math.Inf(1)) if dg == nil { t.Fatal("Directed graph could not be made") } for i := 0; i < 5; i++ { if !dg.Has(Node(i)) { t.Errorf("Node that should exist doesn't: %d", i) } if degree := dg.Degree(Node(i)); degree != 0 { t.Errorf("Node in impassable graph has a neighbor. Node: %d Degree: %d", i, degree) } } for i := 5; i < 10; i++ { if dg.Has(Node(i)) { t.Errorf("Node exists that shouldn't: %d", i) } } } func TestBasicDensePassable(t *testing.T) { dg := NewUndirectedMatrix(5, 1, 0, math.Inf(1)) if dg == nil { t.Fatal("Directed graph could not be made") } for i := 0; i < 5; i++ { if !dg.Has(Node(i)) { t.Errorf("Node that should exist doesn't: %d", i) } if degree := dg.Degree(Node(i)); degree != 4 { t.Errorf("Node in passable graph missing neighbors. Node: %d Degree: %d", i, degree) } } for i := 5; i < 10; i++ { if dg.Has(Node(i)) { t.Errorf("Node exists that shouldn't: %d", i) } } } func TestDirectedDenseAddRemove(t *testing.T) { dg := NewDirectedMatrix(10, math.Inf(1), 0, math.Inf(1)) dg.SetEdge(Edge{F: Node(0), T: Node(2), W: 1}) if neighbors := dg.From(Node(0)); len(neighbors) != 1 || neighbors[0].ID() != 2 || dg.Edge(Node(0), Node(2)) == nil { t.Errorf("Adding edge didn't create successor") } dg.RemoveEdge(Edge{F: Node(0), T: Node(2)}) if neighbors := dg.From(Node(0)); len(neighbors) != 0 || dg.Edge(Node(0), Node(2)) != nil { t.Errorf("Removing edge didn't properly remove successor") } if neighbors := dg.To(Node(2)); len(neighbors) != 0 || dg.Edge(Node(0), Node(2)) != nil { t.Errorf("Removing directed edge wrongly kept predecessor") } dg.SetEdge(Edge{F: Node(0), T: Node(2), W: 2}) // I figure we've torture tested From/To at this point // so we'll just use the bool functions now if dg.Edge(Node(0), Node(2)) == nil { t.Fatal("Adding directed edge didn't change successor back") } c1, _ := dg.Weight(Node(2), Node(0)) c2, _ := dg.Weight(Node(0), Node(2)) if c1 == c2 { t.Error("Adding directed edge affected cost in undirected manner") } } func TestUndirectedDenseAddRemove(t *testing.T) { dg := NewUndirectedMatrix(10, math.Inf(1), 0, math.Inf(1)) dg.SetEdge(Edge{F: Node(0), T: Node(2)}) if neighbors := dg.From(Node(0)); len(neighbors) != 1 || neighbors[0].ID() != 2 || dg.EdgeBetween(Node(0), Node(2)) == nil { t.Errorf("Couldn't add neighbor") } if neighbors := dg.From(Node(2)); len(neighbors) != 1 || neighbors[0].ID() != 0 || dg.EdgeBetween(Node(2), Node(0)) == nil { t.Errorf("Adding an undirected neighbor didn't add it reciprocally") } } func TestDenseLists(t *testing.T) { dg := NewDirectedMatrix(15, 1, 0, math.Inf(1)) nodes := dg.Nodes() if len(nodes) != 15 { t.Fatalf("Wrong number of nodes") } sort.Sort(ordered.ByID(nodes)) for i, node := range dg.Nodes() { if int64(i) != node.ID() { t.Errorf("Node list doesn't return properly id'd nodes") } } edges := dg.Edges() if len(edges) != 15*14 { t.Errorf("Improper number of edges for passable dense graph") } dg.RemoveEdge(Edge{F: Node(12), T: Node(11)}) edges = dg.Edges() if len(edges) != (15*14)-1 { t.Errorf("Removing edge didn't affect edge listing properly") } }