/// <summary>
/// Adds all downward edges.
/// </summary>
/// <param name="graph"></param>
public static void AddDownwardEdges(this IDynamicGraph <CHEdgeData> graph)
{ // add the reverse edges to get a easy depth-first search.
for (uint vertexId = 1; vertexId < graph.VertexCount; vertexId++)
{
List <KeyValuePair <uint, CHEdgeData> > arcs =
new List <KeyValuePair <uint, CHEdgeData> >(graph.GetArcs(vertexId));
foreach (KeyValuePair <uint, CHEdgeData> arc in arcs)
{
if (arc.Value.ToHigher)
{
// create severse edge.
CHEdgeData reverseEdge = new CHEdgeData();
reverseEdge.SetDirection(arc.Value.Backward, arc.Value.Forward, false);
reverseEdge.Weight = arc.Value.Weight;
graph.AddArc(arc.Key, vertexId, reverseEdge, null);
}
}
}
}
/// <summary>
/// Contracts the given vertex.
/// </summary>
/// <param name="vertex"></param>
public void Contract(uint vertex)
{
if (_contracted.Length > vertex && _contracted[vertex])
{
throw new Exception("Is already contracted!");
}
// keep the neighbours.
HashSet<KeyValuePair<uint, CHEdgeData>> neighbours =
new HashSet<KeyValuePair<uint, CHEdgeData>>();
// get all information from the source.
KeyValuePair<uint, CHEdgeData>[] edges = _target.GetArcs(vertex);
// remove all informative edges.
edges = edges.RemoveInformativeEdges();
// report the before contraction event.
this.OnBeforeContraction(vertex, edges);
// remove the edges from the neighbours to the target.
foreach (KeyValuePair<uint, CHEdgeData> edge in edges)
{ // remove the edge.
_target.DeleteArc(edge.Key, vertex);
// keep the neighbour.
if (_keepDirectNeighbours && !edge.Value.HasContractedVertex)
{ // edge does represent a neighbour relation.
neighbours.Add(
new KeyValuePair<uint, CHEdgeData>(edge.Key, edge.Value.ConvertToInformative()));
}
}
// loop over each combination of edges just once.
for (int x = 1; x < edges.Length; x++)
{ // loop over all elements first.
KeyValuePair<uint, CHEdgeData> xEdge = edges[x];
if (xEdge.Value.IsInformative) { continue; }
for (int y = 0; y < x; y++)
{ // loop over all elements.
KeyValuePair<uint, CHEdgeData> yEdge = edges[y];
if (yEdge.Value.IsInformative) { continue; }
// calculate the total weight.
float weight = xEdge.Value.Weight + yEdge.Value.Weight;
// add the combinations of these edges.
if (((xEdge.Value.Backward && yEdge.Value.Forward) ||
(yEdge.Value.Backward && xEdge.Value.Forward)) &&
(xEdge.Key != yEdge.Key))
{ // there is a connection from x to y and there is no witness path.
bool witnessXToY = _witnessCalculator.Exists(_target, xEdge.Key,
yEdge.Key, vertex, weight, 100);
bool witnessYToX = _witnessCalculator.Exists(_target, yEdge.Key,
xEdge.Key, vertex, weight, 100);
// create x-to-y data and edge.
CHEdgeData dataXToY = new CHEdgeData();
bool forward = (xEdge.Value.Backward && yEdge.Value.Forward) &&
!witnessXToY;
bool backward = (yEdge.Value.Backward && xEdge.Value.Forward) &&
!witnessYToX;
dataXToY.SetDirection(forward, backward, true);
dataXToY.Weight = weight;
dataXToY.ContractedVertexId = vertex;
if ((dataXToY.Forward || dataXToY.Backward) ||
!_target.HasArc(xEdge.Key, yEdge.Key))
{ // add the edge if there is usefull info or if there needs to be a neighbour relationship.
_target.AddArc(xEdge.Key, yEdge.Key, dataXToY, _comparer);
}
// create y-to-x data and edge.
CHEdgeData dataYToX = new CHEdgeData();
forward = (yEdge.Value.Backward && xEdge.Value.Forward) &&
!witnessYToX;
backward = (xEdge.Value.Backward && yEdge.Value.Forward) &&
!witnessXToY;
dataYToX.SetDirection(forward, backward, true);
dataYToX.Weight = weight;
dataYToX.ContractedVertexId = vertex;
if ((dataYToX.Forward || dataYToX.Backward) ||
!_target.HasArc(yEdge.Key, xEdge.Key))
{ // add the edge if there is usefull info or if there needs to be a neighbour relationship.
_target.AddArc(yEdge.Key, xEdge.Key, dataYToX, _comparer);
}
}
}
}
// mark the vertex as contracted.
this.MarkContracted(vertex);
// notify a contracted neighbour.
_calculator.NotifyContracted(vertex);
// add contracted neighbour edges again.
if (_keepDirectNeighbours)
{
foreach (KeyValuePair<uint, CHEdgeData> neighbour in neighbours)
{
_target.AddArc(neighbour.Key, vertex, neighbour.Value, null);
}
}
// report the after contraction event.
this.OnAfterContraction(vertex, edges);
}
/// <summary>
/// Contracts the given vertex.
/// </summary>
/// <param name="vertex"></param>
public void Contract(uint vertex)
{
if (_contracted.Length > vertex && _contracted[vertex])
{
throw new Exception("Is already contracted!");
}
// keep the neighbours.
HashSet <KeyValuePair <uint, CHEdgeData> > neighbours =
new HashSet <KeyValuePair <uint, CHEdgeData> >();
// get all information from the source.
KeyValuePair <uint, CHEdgeData>[] edges = _target.GetArcs(vertex);
// remove all informative edges.
edges = edges.RemoveInformativeEdges();
// report the before contraction event.
this.OnBeforeContraction(vertex, edges);
// remove the edges from the neighbours to the target.
foreach (KeyValuePair <uint, CHEdgeData> edge in edges)
{ // remove the edge.
_target.DeleteArc(edge.Key, vertex);
// keep the neighbour.
if (_keepDirectNeighbours && !edge.Value.HasContractedVertex)
{ // edge does represent a neighbour relation.
neighbours.Add(
new KeyValuePair <uint, CHEdgeData>(edge.Key, edge.Value.ConvertToInformative()));
}
}
// loop over each combination of edges just once.
for (int x = 1; x < edges.Length; x++)
{ // loop over all elements first.
KeyValuePair <uint, CHEdgeData> xEdge = edges[x];
if (xEdge.Value.IsInformative)
{
continue;
}
for (int y = 0; y < x; y++)
{ // loop over all elements.
KeyValuePair <uint, CHEdgeData> yEdge = edges[y];
if (yEdge.Value.IsInformative)
{
continue;
}
// calculate the total weight.
float weight = xEdge.Value.Weight + yEdge.Value.Weight;
// add the combinations of these edges.
if (((xEdge.Value.Backward && yEdge.Value.Forward) ||
(yEdge.Value.Backward && xEdge.Value.Forward)) &&
(xEdge.Key != yEdge.Key))
{ // there is a connection from x to y and there is no witness path.
bool witnessXToY = _witnessCalculator.Exists(_target, xEdge.Key,
yEdge.Key, vertex, weight, 100);
bool witnessYToX = _witnessCalculator.Exists(_target, yEdge.Key,
xEdge.Key, vertex, weight, 100);
// create x-to-y data and edge.
CHEdgeData dataXToY = new CHEdgeData();
bool forward = (xEdge.Value.Backward && yEdge.Value.Forward) &&
!witnessXToY;
bool backward = (yEdge.Value.Backward && xEdge.Value.Forward) &&
!witnessYToX;
dataXToY.SetDirection(forward, backward, true);
dataXToY.Weight = weight;
dataXToY.ContractedVertexId = vertex;
if ((dataXToY.Forward || dataXToY.Backward) ||
!_target.HasArc(xEdge.Key, yEdge.Key))
{ // add the edge if there is usefull info or if there needs to be a neighbour relationship.
_target.AddArc(xEdge.Key, yEdge.Key, dataXToY, _comparer);
}
// create y-to-x data and edge.
CHEdgeData dataYToX = new CHEdgeData();
forward = (yEdge.Value.Backward && xEdge.Value.Forward) &&
!witnessYToX;
backward = (xEdge.Value.Backward && yEdge.Value.Forward) &&
!witnessXToY;
dataYToX.SetDirection(forward, backward, true);
dataYToX.Weight = weight;
dataYToX.ContractedVertexId = vertex;
if ((dataYToX.Forward || dataYToX.Backward) ||
!_target.HasArc(yEdge.Key, xEdge.Key))
{ // add the edge if there is usefull info or if there needs to be a neighbour relationship.
_target.AddArc(yEdge.Key, xEdge.Key, dataYToX, _comparer);
}
}
}
}
// mark the vertex as contracted.
this.MarkContracted(vertex);
// notify a contracted neighbour.
_calculator.NotifyContracted(vertex);
// add contracted neighbour edges again.
if (_keepDirectNeighbours)
{
foreach (KeyValuePair <uint, CHEdgeData> neighbour in neighbours)
{
_target.AddArc(neighbour.Key, vertex, neighbour.Value, null);
}
}
// report the after contraction event.
this.OnAfterContraction(vertex, edges);
}
/// <summary>
/// Tests the set direction functionality for the given parameters.
/// </summary>
/// <param name="edge"></param>
/// <param name="forward"></param>
/// <param name="backward"></param>
/// <param name="toHigher"></param>
private void DoTestSetDirection(CHEdgeData edge, bool forward, bool backward, bool toHigher)
{
edge.SetDirection(forward, backward, toHigher);
if (forward) { Assert.IsTrue(edge.Forward); }
else { Assert.IsFalse(edge.Forward); }
if (backward) { Assert.IsTrue(edge.Backward); }
else { Assert.IsFalse(edge.Backward); }
if (toHigher) { Assert.IsTrue(edge.ToHigher); }
else { Assert.IsFalse(edge.ToHigher); }
}
/// <summary>
/// Contracts the given vertex.
/// </summary>
/// <param name="vertex"></param>
public void Contract(uint vertex)
{
if (_contracted.Length > vertex && _contracted[vertex])
{
throw new Exception("Is already contracted!");
}
// keep the neighbours.
var neighbours = new HashSet <KeyValuePair <uint, CHEdgeData> >();
// get all information from the source.
var edges = _target.GetEdges(vertex);
// report the before contraction event.
this.OnBeforeContraction(vertex, edges);
// replace the adjacent edges with edges that are point up.
var edgesForContractions = new List <KeyValuePair <uint, CHEdgeData> >(edges.Length);
foreach (var edge in edges)
{
if (!edge.Value.ToLower && !edge.Value.ToHigher)
{ // the edge is not to lower or higher.
// use this edge for contraction.
edgesForContractions.Add(edge);
// overwrite the old edge making it point 'to higher' only.
_target.AddEdge(vertex, edge.Key,
new CHEdgeData(edge.Value.Weight, edge.Value.Forward, edge.Value.Backward, true, edge.Value.ContractedVertexId, edge.Value.Tags), null);
}
}
// loop over each combination of edges just once.
for (int x = 1; x < edgesForContractions.Count; x++)
{ // loop over all elements first.
var xEdge = edgesForContractions[x];
for (int y = 0; y < x; y++)
{ // loop over all elements.
var yEdge = edgesForContractions[y];
// calculate the total weight.
var weight = xEdge.Value.Weight + yEdge.Value.Weight;
// add the combinations of these edges.
if (((xEdge.Value.Backward && yEdge.Value.Forward) ||
(yEdge.Value.Backward && xEdge.Value.Forward)) &&
(xEdge.Key != yEdge.Key))
{ // there is a connection from x to y and there is no witness path.
var witnessXToY = _contractionWitnessCalculator.Exists(_target, xEdge.Key,
yEdge.Key, vertex, weight, int.MaxValue);
var witnessYToX = _contractionWitnessCalculator.Exists(_target, yEdge.Key,
xEdge.Key, vertex, weight, int.MaxValue);
// create x-to-y data and edge.
var dataXToY = new CHEdgeData();
var forward = (xEdge.Value.Backward && yEdge.Value.Forward) &&
!witnessXToY;
var backward = (yEdge.Value.Backward && xEdge.Value.Forward) &&
!witnessYToX;
if ((forward || backward) ||
!_target.ContainsEdge(xEdge.Key, yEdge.Key))
{ // add the edge if there is usefull info or if there needs to be a neighbour relationship.
dataXToY.SetDirection(forward, backward);
dataXToY.Weight = weight;
dataXToY.ContractedVertexId = vertex;
_target.AddEdge(xEdge.Key, yEdge.Key, dataXToY, null, _comparer);
}
}
}
}
// mark the vertex as contracted.
this.MarkContracted(vertex);
// notify a contracted neighbour.
_calculator.NotifyContracted(vertex);
// report the after contraction event.
this.OnAfterContraction(vertex, edges);
}
