public void Sort()
{
AdjacencyGraph g = new AdjacencyGraph(new VertexAndEdgeProvider(), true);
Hashtable iv = new Hashtable();
int i = 0;
IVertex a = g.AddVertex();
iv[i++]=a;
IVertex b = g.AddVertex();
iv[i++]=b;
IVertex c = g.AddVertex();
iv[i++]=c;
IVertex d = g.AddVertex();
iv[i++]=d;
IVertex e = g.AddVertex();
iv[i++]=e;
g.AddEdge(a,b);
g.AddEdge(a,c);
g.AddEdge(b,c);
g.AddEdge(c,d);
g.AddEdge(a,e);
TopologicalSortAlgorithm topo = new TopologicalSortAlgorithm(g);
topo.Compute();
for(int j=0;j<topo.SortedVertices.Count;++j)
{
Assert.AreEqual( (IVertex)iv[j], topo.SortedVertices[j]);
}
}
public void SortCyclicPUT_NEW(AdjacencyGraph g, IVertex[] listOfVertices, bool rndConstructor)
{
TopologicalSortAlgorithm topo;// = new TopologicalSortAlgorithm(g);
List<IVertex> list = null;
if (listOfVertices != null && g!= null)
{
list = new List<IVertex>();
foreach (IVertex v in listOfVertices)
{
IVertex a = g.AddVertex();
list.Add(v);
}
g = createCycle(g);
}
if (rndConstructor)
topo = new TopologicalSortAlgorithm(g, list);
else
topo = new TopologicalSortAlgorithm(g);
topo.Compute();
for (int j = 0; j < topo.SortedVertices.Count; ++j)
{
PexObserve.ValueForViewing<IVertex>("Sorted Vertex", (IVertex)topo.SortedVertices[j]);
}
}
public void Sort()
{
AdjacencyGraph g = new AdjacencyGraph(true);
Hashtable iv = new Hashtable();
int i = 0;
IVertex a = g.AddVertex();
iv[i++]=a;
IVertex b = g.AddVertex();
iv[i++]=b;
IVertex c = g.AddVertex();
iv[i++]=c;
IVertex d = g.AddVertex();
iv[i++]=d;
IVertex e = g.AddVertex();
iv[i++]=e;
g.AddEdge(a,b);
g.AddEdge(a,c);
g.AddEdge(b,c);
g.AddEdge(c,d);
g.AddEdge(a,e);
TopologicalSortAlgorithm topo = new TopologicalSortAlgorithm(g);
topo.Compute();
}
public void OneTwo()
{
var graph = new AdjacencyGraph<int, Edge<int>>();
graph.AddVertex(1);
graph.AddVertex(2);
graph.AddEdge(new Edge<int>(1, 2));
var t = new TopologicalSortAlgorithm<int, Edge<int>>(graph);
t.Compute();
}
protected override void RunFixtures()
{
// setup result
foreach (FixtureVertex v in this.FixtureGraph.Graph.Vertices)
v.Result = ReportRunResult.NotRun;
// topological sort
TopologicalSortAlgorithm topo = new TopologicalSortAlgorithm(this.FixtureGraph.Graph);
ArrayList list = new ArrayList();
topo.Compute(list);
// execute pipes
foreach (FixtureVertex v in list)
{
// result failed
if (v.Result != ReportRunResult.NotRun)
{
ReportMonitor monitor = new ReportMonitor();
ParentFixtureFailedException ex = new ParentFixtureFailedException();
foreach (Fixture fixture in v.Fixtures)
{
if (!this.FilterFixture(fixture))
continue;
this.SkipStarters(fixture, ex);
}
}
else
{
// run fixtures
v.Result = ReportRunResult.Success;
foreach (Fixture fixture in v.Fixtures)
{
if (!this.FilterFixture(fixture))
continue;
ReportRunResult result = RunFixture(fixture);
if (result != ReportRunResult.Success && v.Result != ReportRunResult.Failure)
v.Result = result;
}
}
// update children if failed
if (v.Result != ReportRunResult.Success)
{
foreach (FixtureVertex target in this.FixtureGraph.Graph.AdjacentVertices(v))
{
target.Result = v.Result;
}
}
}
}
/// <summary>
/// Applies a topological sort to the graph
/// </summary>
/// <param name="g">graph to sort</param>
/// <param name="vertices">sorted vertices</param>
public static void TopologicalSort(IVertexListGraph g, IList vertices)
{
if (g == null)
{
throw new ArgumentNullException("g");
}
if (vertices == null)
{
throw new ArgumentNullException("vertices");
}
vertices.Clear();
TopologicalSortAlgorithm topo =
new TopologicalSortAlgorithm(g, vertices);
topo.Compute();
}
/// <summary>
/// Compute the transitive closure and store it in the supplied graph 'tc'
/// </summary>
/// <param name="tc">
/// Mutable Graph instance to store the transitive closure
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="tc"/> is a <null/>.
/// </exception>
public void Create(IMutableVertexAndEdgeListGraph tc)
{
if (tc == null)
{
throw new ArgumentNullException("tc");
}
CondensationGraphAlgorithm cgalgo = new CondensationGraphAlgorithm(VisitedGraph);
cgalgo.Create(cg);
ArrayList topo_order = new ArrayList(cg.VerticesCount);
TopologicalSortAlgorithm topo = new TopologicalSortAlgorithm(cg, topo_order);
topo.Compute();
VertexIntDictionary in_a_chain = new VertexIntDictionary();
VertexIntDictionary topo_number = new VertexIntDictionary();
for (int order = 0; order < topo_order.Count; order++)
{
IVertex v = (IVertex)topo_order[order];
topo_number.Add(v, order);
if (!in_a_chain.Contains(v)) // Initially no vertex is present in a chain
{
in_a_chain.Add(v, 0);
}
}
VertexListMatrix chains = new VertexListMatrix();
int position = -1;
foreach (IVertex v in topo_order)
{
if (in_a_chain[v] == 0)
{
// Start a new chain
position = chains.AddRow();
IVertex next = v;
for (;;)
{
chains[position].Add(next);
in_a_chain[next] = 1;
// Get adjacent vertices ordered by topological number
// Extend the chain by choosing the adj vertex with lowest topo#
ArrayList adj = TopoSortAdjVertices(next, cg, topo_number);
if ((next = FirstNotInChain(adj, in_a_chain)) == null)
{
break;
}
}
}
}
VertexIntDictionary chain_number = new VertexIntDictionary();
VertexIntDictionary pos_in_chain = new VertexIntDictionary();
// Record chain positions of vertices
SetChainPositions(chains, chain_number, pos_in_chain);
VertexListMatrix successors = new VertexListMatrix();
successors.CreateObjectMatrix(cg.VerticesCount, chains.RowCount, int.MaxValue);
if (topo_order.Count > 0)
{
for (int rtopo = topo_order.Count - 1; rtopo > -1; rtopo--)
{
IVertex u = (IVertex)topo_order[rtopo];
foreach (IVertex v in TopoSortAdjVertices(u, cg, topo_number))
{
if (topo_number[v] < (int)successors[u.ID][chain_number[v]])
{
// {succ(u)} = {succ(u)} U {succ(v)}
LeftUnion(successors[u.ID], successors[v.ID]);
// {succ(u)} = {succ(u)} U {v}
successors[u.ID][chain_number[v]] = topo_number[v];
}
}
}
}
// Create transitive closure of condensation graph
// Remove existing edges in CG & rebuild edges for TC from
// successor set (to avoid duplicating parallel edges)
ArrayList edges = new ArrayList();
foreach (IEdge e in cg.Edges)
{
edges.Add(e);
}
foreach (IEdge e in edges)
{
cg.RemoveEdge(e);
}
foreach (IVertex u in cg.Vertices)
{
int i = u.ID;
for (int j = 0; j < chains.RowCount; j++)
{
int tnumber = (int)successors[i][j];
if (tnumber < int.MaxValue)
{
IVertex v = (IVertex)topo_order[tnumber];
for (int k = pos_in_chain[v]; k < chains[j].Count; k++)
{
cg.AddEdge(u, (IVertex)chains[j][k]);
}
}
}
}
// Maps a vertex in input graph to it's transitive closure graph
graphTransitiveClosures = new VertexVertexDictionary();
// Add vertices to transitive closure graph
foreach (IVertex v in visitedGraph.Vertices)
{
if (!graphTransitiveClosures.Contains(v))
{
IVertex vTransform = tc.AddVertex();
OnInitTransitiveClosureVertex(
new TransitiveClosureVertexEventArgs(
v, vTransform)
);
// Fire the TC Vertex Event
graphTransitiveClosures.Add(v, vTransform);
}
}
//Add edges connecting vertices within SCC & adjacent
// SCC (strongly connected component)
IVertexCollection scc_vertices = null;
foreach (IVertex s_tccg in cg.Vertices)
{
scc_vertices = (IVertexCollection)cgalgo.SCCVerticesMap[s_tccg.ID];
if (scc_vertices.Count > 1)
{
foreach (IVertex u in scc_vertices)
{
foreach (IVertex v in scc_vertices)
{
OnExamineEdge(tc.AddEdge(graphTransitiveClosures[u], graphTransitiveClosures[v]));
}
}
}
foreach (IEdge adj_edge in cg.OutEdges(s_tccg))
{
IVertex t_tccg = adj_edge.Target;
foreach (IVertex s in (IVertexCollection)cgalgo.SCCVerticesMap[s_tccg.ID])
{
foreach (IVertex t in (IVertexCollection)cgalgo.SCCVerticesMap[t_tccg.ID])
{
OnExamineEdge(tc.AddEdge(graphTransitiveClosures[s], graphTransitiveClosures[t]));
}
}
}
}
}
/// <summary>
/// Applies a topological sort to the graph
/// </summary>
/// <param name="g">graph to sort</param>
/// <param name="vertices">sorted vertices</param>
public static void TopologicalSort(IVertexListGraph g, IList vertices)
{
if (g==null)
throw new ArgumentNullException("g");
if (vertices==null)
throw new ArgumentNullException("vertices");
vertices.Clear();
TopologicalSortAlgorithm topo =
new TopologicalSortAlgorithm(g,vertices);
topo.Compute();
}
public void SetTestAssembly(Assembly testAssembly)
{
if (testAssembly == null)
throw new ArgumentNullException("testAssembly");
this.testAssembly = testAssembly;
this.explorer = new FixtureExplorer(this.testAssembly);
this.topo = new TopologicalSortAlgorithm(
this.Explorer.FixtureGraph.Graph);
}
public void FacebookSeattleWordPuzzle()
{
/* A puzzle from Facebook Seattle opening party:
* http://www.facebook.com/note.php?note_id=146727365346299
* You are given a list of relationships between the letters in a single word, all of which are in the form:
* "The first occurrence of A comes before N occurrences of B."
* You can safely assume that you have all such relationships except for any in which N would be 0.
* Determine the original word, then go to http://www.facebook.com/seattle/[insert-word-here] to find the second part of the puzzle.
*
* The first occurrence of 'e' comes before 1 occurrence of 's'.
* The first occurrence of 'i' comes before 1 occurrence of 'n'.
* The first occurrence of 'i' comes before 1 occurrence of 'i'.
* The first occurrence of 'n' comes before 2 occurrences of 'e'.
* The first occurrence of 'e' comes before 1 occurrence of 'e'.
* The first occurrence of 'i' comes before 1 occurrence of 'v'.
* The first occurrence of 'n' comes before 1 occurrence of 'i'.
* The first occurrence of 'n' comes before 1 occurrence of 'v'.
* The first occurrence of 'i' comes before 1 occurrence of 's'.
* The first occurrence of 't' comes before 1 occurrence of 's'.
* The first occurrence of 'v' comes before 1 occurrence of 's'.
* The first occurrence of 'v' comes before 2 occurrences of 'e'.
* The first occurrence of 't' comes before 2 occurrences of 'e'.
* The first occurrence of 'i' comes before 2 occurrences of 'e'.
* The first occurrence of 'v' comes before 1 occurrence of 't'.
* The first occurrence of 'n' comes before 1 occurrence of 't'.
* The first occurrence of 'v' comes before 1 occurrence of 'i'.
* The first occurrence of 'i' comes before 1 occurrence of 't'.
* The first occurrence of 'n' comes before 1 occurrence of 's'.
*/
var graph = new AdjacencyGraph <Letter, Edge <Letter> >();
//A more generalized algorithm would handle duplicate letters automatically.
//This is the quick and dirty solution.
var i1 = new Letter('i');
var i2 = new Letter('i');
var e1 = new Letter('e');
var e2 = new Letter('e');
var s = new Letter('s');
var n = new Letter('n');
var t = new Letter('t');
var v = new Letter('v');
graph.AddVertexRange(new List <Letter> {
e1, e2, s, i1, i2, n, t, v
});
graph.AddEdge(new Edge <Letter>(e1, s));
graph.AddEdge(new Edge <Letter>(i1, n));
graph.AddEdge(new Edge <Letter>(i1, i2));
graph.AddEdge(new Edge <Letter>(n, e1));
graph.AddEdge(new Edge <Letter>(n, e2));
graph.AddEdge(new Edge <Letter>(e1, e2));
graph.AddEdge(new Edge <Letter>(i1, v));
graph.AddEdge(new Edge <Letter>(n, e1));
graph.AddEdge(new Edge <Letter>(n, v));
graph.AddEdge(new Edge <Letter>(i1, s));
graph.AddEdge(new Edge <Letter>(t, s));
graph.AddEdge(new Edge <Letter>(v, s));
graph.AddEdge(new Edge <Letter>(v, e1));
graph.AddEdge(new Edge <Letter>(v, e2));
graph.AddEdge(new Edge <Letter>(t, e1));
graph.AddEdge(new Edge <Letter>(t, e2));
graph.AddEdge(new Edge <Letter>(i1, e1));
graph.AddEdge(new Edge <Letter>(i1, e2));
graph.AddEdge(new Edge <Letter>(v, t));
graph.AddEdge(new Edge <Letter>(n, t));
graph.AddEdge(new Edge <Letter>(v, i2));
graph.AddEdge(new Edge <Letter>(i1, t));
graph.AddEdge(new Edge <Letter>(n, s));
var sort = new TopologicalSortAlgorithm <Letter, Edge <Letter> >(graph);
sort.Compute();
StringBuilder builder = new StringBuilder();
foreach (var item in sort.SortedVertices)
{
builder.Append(item.ToString());
}
var word = builder.ToString();
Assert.AreEqual("invitees", word);
}
public ReportResult RunTests()
{
ReportResult result = new ReportResult();
if (graph.VerticesCount == 0)
{
this.OnLog("No assembly to execute");
result.UpdateCounts();
return result;
}
this.OnLog("Sorting assemblies by dependencies");
// create topological sort
ArrayList sortedVertices = new ArrayList();
TopologicalSortAlgorithm topo = new TopologicalSortAlgorithm(graph);
topo.Compute(sortedVertices);
if (sortedVertices.Count == 0)
throw new InvalidOperationException("Cannot be zero");
// set vertices colors
this.OnLog("etting up fixture colors");
VertexColorDictionary colors = new VertexColorDictionary();
foreach (TestDomainVertex v in graph.Vertices)
colors.Add(v, GraphColor.White);
// execute each domain
foreach (TestDomainVertex v in sortedVertices)
{
// if vertex color is not white, skip it
GraphColor color = colors[v];
if (color != GraphColor.White)
{
this.OnLog("Skipping assembly {0} because dependent assembly failed", v.Domain.TestEngine.Explorer.AssemblyName);
// mark children
foreach (TestDomainVertex child in graph.AdjacentVertices(v))
colors[child] = GraphColor.Black;
continue;
}
this.OnLog("Loading {0}", v.Domain.TestEngine.Explorer.AssemblyName);
ReportCounter counter = v.Domain.TestEngine.GetTestCount();
this.OnLog("Found {0} tests", counter.RunCount);
this.OnLog("Running fixtures.");
v.Domain.TestEngine.RunPipes();
counter = v.Domain.TestEngine.GetTestCount();
this.OnLog("Tests finished: {0} tests, {1} success, {2} failures, {3} ignored"
, counter.RunCount
, counter.SuccessCount
, counter.FailureCount
, counter.IgnoreCount
);
result.Merge(v.Domain.TestEngine.Report.Result);
if (counter.FailureCount != 0)
{
// mark children as failed
colors[v] = GraphColor.Black;
foreach (TestDomainVertex child in graph.AdjacentVertices(v))
colors[child] = GraphColor.Black;
}
else
{
// mark vertex as succesfull
colors[v] = GraphColor.Gray;
}
}
result.UpdateCounts();
MbUnit.Framework.Assert.IsNotNull(result);
MbUnit.Framework.Assert.IsNotNull(result.Counter);
this.OnLog("All Tests finished: {0} tests, {1} success, {2} failures, {3} ignored in {4} seconds"
, result.Counter.RunCount
, result.Counter.SuccessCount
, result.Counter.FailureCount
, result.Counter.IgnoreCount
, result.Counter.Duration
);
return result;
}
public void SortCyclic()
{
AdjacencyGraph g = new AdjacencyGraph(new VertexAndEdgeProvider(), true);
IVertex a = g.AddVertex();
IVertex b = g.AddVertex();
IVertex c = g.AddVertex();
IVertex d = g.AddVertex();
IVertex e = g.AddVertex();
g.AddEdge(a,b);
g.AddEdge(a,c);
g.AddEdge(b,c);
g.AddEdge(c,d);
g.AddEdge(a,e);
g.AddEdge(c,a);
TopologicalSortAlgorithm topo = new TopologicalSortAlgorithm(g);
topo.Compute();
}
public void SortCyclic(
[PexAssumeNotNull]IVertexListGraph<string,Edge<string>> g)
{
TopologicalSortAlgorithm<string, Edge<string>> topo = new TopologicalSortAlgorithm<string, Edge<string>>(g);
topo.Compute();
}
/// <summary>
/// Compute the transitive closure and store it in the supplied graph 'tc'
/// </summary>
/// <param name="tc">
/// Mutable Graph instance to store the transitive closure
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="tc"/> is a <null/>.
/// </exception>
public void Create( IMutableVertexAndEdgeListGraph tc )
{
if (tc==null)
throw new ArgumentNullException("tc");
CondensationGraphAlgorithm cgalgo = new CondensationGraphAlgorithm(VisitedGraph);
cgalgo.Create(cg);
ArrayList topo_order = new ArrayList(cg.VerticesCount);
TopologicalSortAlgorithm topo = new TopologicalSortAlgorithm(cg, topo_order);
topo.Compute();
VertexIntDictionary in_a_chain= new VertexIntDictionary();
VertexIntDictionary topo_number = new VertexIntDictionary();
for( int order=0; order<topo_order.Count; order++ ) {
IVertex v = (IVertex)topo_order[order];
topo_number.Add( v, order );
if(!in_a_chain.Contains(v)) // Initially no vertex is present in a chain
in_a_chain.Add(v, 0);
}
VertexListMatrix chains = new VertexListMatrix();
int position = -1;
foreach( IVertex v in topo_order )
{
if(in_a_chain[v]==0) {
// Start a new chain
position = chains.AddRow();
IVertex next = v;
for(;;) {
chains[position].Add(next);
in_a_chain[next] = 1;
// Get adjacent vertices ordered by topological number
// Extend the chain by choosing the adj vertex with lowest topo#
ArrayList adj = TopoSortAdjVertices(next, cg, topo_number);
if( (next = FirstNotInChain(adj, in_a_chain)) == null )
break;
}
}
}
VertexIntDictionary chain_number = new VertexIntDictionary();
VertexIntDictionary pos_in_chain = new VertexIntDictionary();
// Record chain positions of vertices
SetChainPositions(chains, chain_number, pos_in_chain);
VertexListMatrix successors = new VertexListMatrix();
successors.CreateObjectMatrix(cg.VerticesCount, chains.RowCount, int.MaxValue);
if(topo_order.Count > 0)
{
for( int rtopo=topo_order.Count-1; rtopo>-1; rtopo--)
{
IVertex u = (IVertex) topo_order[rtopo];
foreach( IVertex v in TopoSortAdjVertices(u, cg, topo_number) )
{
if(topo_number[v] < (int)successors[u.ID][chain_number[v]])
{
// {succ(u)} = {succ(u)} U {succ(v)}
LeftUnion(successors[u.ID], successors[v.ID]);
// {succ(u)} = {succ(u)} U {v}
successors[u.ID][chain_number[v]] = topo_number[v];
}
}
}
}
// Create transitive closure of condensation graph
// Remove existing edges in CG & rebuild edges for TC from
// successor set (to avoid duplicating parallel edges)
ArrayList edges = new ArrayList();
foreach( IEdge e in cg.Edges )
edges.Add(e);
foreach(IEdge e in edges)
cg.RemoveEdge(e);
foreach(IVertex u in cg.Vertices)
{
int i = u.ID;
for(int j=0; j<chains.RowCount; j++)
{
int tnumber = (int) successors[i][j];
if(tnumber < int.MaxValue)
{
IVertex v = (IVertex) topo_order[tnumber];
for(int k=pos_in_chain[v]; k<chains[j].Count; k++)
{
cg.AddEdge( u, (IVertex)chains[j][k]);
}
}
}
}
// Maps a vertex in input graph to it's transitive closure graph
graphTransitiveClosures = new VertexVertexDictionary();
// Add vertices to transitive closure graph
foreach(IVertex v in visitedGraph.Vertices)
{
if(!graphTransitiveClosures.Contains(v))
{
IVertex vTransform = tc.AddVertex();
OnInitTransitiveClosureVertex(
new TransitiveClosureVertexEventArgs(
v, vTransform)
);
// Fire the TC Vertex Event
graphTransitiveClosures.Add(v, vTransform);
}
}
//Add edges connecting vertices within SCC & adjacent
// SCC (strongly connected component)
IVertexCollection scc_vertices = null;
foreach(IVertex s_tccg in cg.Vertices)
{
scc_vertices = (IVertexCollection)cgalgo.SCCVerticesMap[s_tccg.ID];
if(scc_vertices.Count > 1)
{
foreach(IVertex u in scc_vertices)
foreach(IVertex v in scc_vertices)
OnExamineEdge(tc.AddEdge(graphTransitiveClosures[u], graphTransitiveClosures[v]));
}
foreach(IEdge adj_edge in cg.OutEdges(s_tccg))
{
IVertex t_tccg = adj_edge.Target;
foreach(IVertex s in (IVertexCollection)cgalgo.SCCVerticesMap[s_tccg.ID])
{
foreach(IVertex t in (IVertexCollection)cgalgo.SCCVerticesMap[t_tccg.ID])
OnExamineEdge(tc.AddEdge(graphTransitiveClosures[s], graphTransitiveClosures[t]));
}
}
}
}
public void SortCyclicPUT_NEW1(AdjacencyGraph g, bool rndConstructor, bool allowParallelEdges, int numberOfVertices, bool toNull)
{
g = AdjacencyGraphFactory.CreateAcyclicGraph1(allowParallelEdges, numberOfVertices, toNull);
TopologicalSortAlgorithm topo;
List<IVertex> list = null;
if (g != null && g.VerticesCount > 0)
{
list = new List<IVertex>();
foreach (IVertex v in g.Vertices)
{
IVertex a = g.AddVertex();
list.Add(v);
}
g = createCycle(g);
}
if (rndConstructor)
topo = new TopologicalSortAlgorithm(g, list);
else
topo = new TopologicalSortAlgorithm(g);
topo.Compute();
for (int j = 0; j < topo.SortedVertices.Count; ++j)
{
PexObserve.ValueForViewing<IVertex>("Sorted Vertex", (IVertex)topo.SortedVertices[j]);
}
}
public void SortPUT_NEW(bool allowParallelEdges_b, int numberOfVertices, bool toNull, bool makeNull)
{
TopologicalSortAlgorithm topo = null;
AdjacencyGraph g = null;
if(!makeNull)
g = AdjacencyGraphFactory.CreateAcyclicGraph1(allowParallelEdges_b, numberOfVertices, toNull);
else
topo = new TopologicalSortAlgorithm(g);
Hashtable iv = new Hashtable();
int i = 0;
IVertex a = g.AddVertex();
iv[i++] = a;
IVertex b = g.AddVertex();
iv[i++] = b;
IVertex c = g.AddVertex();
iv[i++] = c;
IVertex d = g.AddVertex();
iv[i++] = d;
IVertex e = g.AddVertex();
iv[i++] = e;
g.AddEdge(a, b);
g.AddEdge(a, c);
g.AddEdge(b, c);
g.AddEdge(c, d);
g.AddEdge(a, e);
topo = new TopologicalSortAlgorithm(g);
topo.Compute();
for (int j = 0; j < topo.SortedVertices.Count; ++j)
{
//PexAssert.AreEqual((IVertex)iv[j], topo.SortedVertices[j]);
PexObserve.ValueForViewing<IVertex>("Sorted Vertex", (IVertex)topo.SortedVertices[j]);
}
}