Ejemplo n.º 1
0
        public void TestServer()
        {
            Tensorflow.ServerDef def        = new ServerDef();
            ClusterDef           clusterDef = new ClusterDef();
            JobDef jd = new JobDef();

            clusterDef.Job.Add(jd);

            def.Cluster = clusterDef;
            byte[] pbuff;
            using (MemoryStream ms = new MemoryStream())
            {
                def.WriteTo(ms);
                pbuff = ms.ToArray();
            }

            /*
             * using (Emgu.TF.Server s = new Emgu.TF.Server(pbuff))
             * {
             *  String target = s.Target;
             * }*/
        }
Ejemplo n.º 2
0
        public SimCluster(ClusterDef cluster, SimRuntime runtime)
        {
            Runtime = runtime;
            Rand    = Runtime.Rand;

            // we register each link as a network service
            foreach (var(id, def) in cluster.Routes)
            {
                var service   = new ServiceId($"network:{id.Source}->{id.Destinaton}");
                var scheduler = new SimScheduler(Runtime, service);
                Routes.Add(id, new SimRoute(scheduler, this, id, def));
            }

            foreach (var machine in cluster.Services.GroupBy(i => i.Key.Machine))
            {
                var m = new SimMachine(machine.Key, runtime, this);

                foreach (var pair in machine)
                {
                    m.Install(pair.Key, pair.Value);
                }
                Machines.Add(machine.Key, m);
            }
        }
 internal bool CheckResult(VariableDef[] variableDefs, ClusterDef[] clusterDefs,
                 ConstraintDef[] constraintDefsX, ConstraintDef[] constraintDefsY,
                 double[] expectedPositionsX, double[] expectedPositionsY,
                 bool checkResults)
 {
     for (uint id = 0; id < variableDefs.Length; ++id)
     {
         variableDefs[id].SetExpected(id, expectedPositionsX[id], expectedPositionsY[id]);
     }
     return CheckResult(variableDefs, clusterDefs, constraintDefsX, constraintDefsY, checkResults);
 }
        private void VerifyClustersDoNotOverlapWithNonChildNodesInTheirOwnHierarchy(double epsilon, KeyValuePair<List<ClusterDef>, List<VariableDef>> kvpCurHier, ClusterDef[] localClusDefs, ref bool succeeded)
        {
            int idxStartVar = 0;
            foreach (ClusterDef clusCur in localClusDefs)
            {
                if (clusCur.IsEmpty)
                {
                    continue;
                }

                VariableDef[] localVarDefs = kvpCurHier.Value.OrderBy(varDef => varDef.Top).ToArray();
                for (int jj = idxStartVar; jj < localVarDefs.Length; ++jj)
                {
                    VariableDef varCheck = localVarDefs[jj];

                    // Minimize variable-list traversal.
                    if (varCheck.Top < (clusCur.Top - epsilon))
                    {
                        idxStartVar = jj;
                    }

                    // If the variable ends before the cluster starts, there's no overlap.
                    if ((clusCur.Top - varCheck.Bottom - this.MinPaddingY) > -epsilon)
                    {
                        continue;
                    }

                    // Rounding error may leave these calculations slightly greater or less than zero.
                    // Since margin is calculated only for inner edges and here we are testing for
                    // sibling rather than nested nodes, we don't use margin here.
                    // Name is <relativeToVarCur><RelativeToVarCheck>
                    double bottomTopOverlap = varCheck.Top - clusCur.Bottom - this.MinPaddingY;
                    if (bottomTopOverlap >= -epsilon)
                    {
                        // Out of range of clusCur's size, so we're done with clusCur.
                        break;
                    }

                    // Does varCheck's left or right border overlap?  Negative overlap means yes.
                    // Again, margins are only cluster-internal and we're testing external boundaries
                    // here; so the cluster size should have been calculated large enough and we only
                    // look at padding.
                    double xa = varCheck.Left - clusCur.Right - this.MinPaddingX;
                    double xb = clusCur.Left - varCheck.Right - this.MinPaddingX;

                    if ((xa < -epsilon) && (xb < -epsilon))
                    {
                        // Let's see if it's an ancestor.
                        bool hasSideOverlap = true;
                        foreach (ClusterDef clusDefParent in varCheck.ParentClusters)
                        {
                            for (ClusterDef clusDefAncestor = clusDefParent; null != clusDefAncestor; clusDefAncestor = clusDefAncestor.ParentClusterDef)
                            {
                                if (clusDefAncestor == clusCur)
                                {
                                    hasSideOverlap = false;
                                    break;
                                }
                            }
                            if (!hasSideOverlap)
                            {
                                break;
                            }
                        }

                        if (hasSideOverlap)
                        {
                            // Uh oh.
                            this.WriteLine("Error {0}: Overlap exists between Cluster '{1}' and non-child Node '{2}'", FailTag("OlapClusNode"),
                                clusCur.ClusterId, varCheck.IdString);
                            this.WriteLine("   Cluster {0}: L/R T/B {1:F5}/{2:F5} {3:F5}/{4:F5}", clusCur.ClusterId,
                                clusCur.Left, clusCur.Right, clusCur.Top, clusCur.Bottom);
                            this.WriteLine("      Node {0}: L/R T/B {1:F5}/{2:F5} {3:F5}/{4:F5}", varCheck.IdString,
                                varCheck.Left, varCheck.Right, varCheck.Top, varCheck.Bottom);
                            succeeded = false;
                        }
                    } // endif overlap within epsilon
                } // endfor each non-child variable
            }
        }
        private void VerifyClustersDoNotOverlapWithNonParentClustersInTheirOwnHierarchy(double epsilon, out ClusterDef[] localClusDefs, KeyValuePair<List<ClusterDef>, List<VariableDef>> kvpCurHier, ref bool succeeded)
        {
            localClusDefs = kvpCurHier.Key.OrderBy(clusDef => clusDef.Top).ToArray();
            for (int ii = 0; ii < localClusDefs.Length; ++ii)
            {
                ClusterDef clusCur = localClusDefs[ii];
                if (clusCur.IsEmpty || clusCur.IsNewHierarchy)
                {
                    continue;
                }
                for (int jj = ii + 1; jj < localClusDefs.Length; ++jj)
                {
                    ClusterDef clusCheck = localClusDefs[jj];
                    if (clusCheck.IsEmpty || clusCheck.IsNewHierarchy)
                    {
                        continue;
                    }

                    // Rounding error may leave these calculations slightly greater or less than zero.
                    // Since margin is calculated only for inner edges and here we are testing for
                    // sibling rather than nested nodes, we don't use margin here.
                    // Name is <relativeToVarCur><RelativeToVarCheck>
                    double bottomTopOverlap = clusCheck.Top - clusCur.Bottom - this.MinPaddingY;
                    if (bottomTopOverlap >= -epsilon)
                    {
                        // Out of range of clusCur's size, so we're done with clusCur.
                        break;
                    }

                    // Does clusCheck's left or right border overlap?  Negative overlap means yes.
                    // Again, margins are only cluster-internal and we're testing external boundaries
                    // here; so the cluster size should have been calculated large enough and we only
                    // look at padding.
                    double xa = clusCheck.Left - clusCur.Right - this.MinPaddingX;
                    double xb = clusCur.Left - clusCheck.Right - this.MinPaddingX;

                    if ((xa < -epsilon) && (xb < -epsilon))
                    {
                        // Let's see if it's a parent.
                        bool hasSideOverlap = true;
                        for (ClusterDef clusDefParent = clusCheck.ParentClusterDef; null != clusDefParent; clusDefParent = clusDefParent.ParentClusterDef)
                        {
                            if (clusDefParent == clusCur)
                            {
                                hasSideOverlap = false;
                                break;
                            }
                        }

                        // Note: This test may fail if clusCheck is a parent of clusCur, but in that case
                        // clusCheck should be outside clusCur - which means we had another error before this,
                        // that cluster {clusCheck} is outside the bounds of parent cluster {clusCur}.
                        if (hasSideOverlap)
                        {
                            // Uh oh.
                            this.WriteLine("Error {0}: Overlap exists between sibling Clusters '{1}' and '{2}'", FailTag("OlapSibClus"),
                                clusCur.ClusterId, clusCheck.ClusterId);
                            this.WriteLine("   Cluster {0}: L/R T/B {1:F5}/{2:F5} {3:F5}/{4:F5}", clusCur.ClusterId,
                                clusCur.Left, clusCur.Right, clusCur.Top, clusCur.Bottom);
                            this.WriteLine("   Cluster {0}: L/R T/B {1:F5}/{2:F5} {3:F5}/{4:F5}", clusCheck.ClusterId,
                                clusCheck.Left, clusCheck.Right, clusCheck.Top, clusCheck.Bottom);
                            succeeded = false;
                        }
                    } // endif overlap within epsilon
                } // endfor localClusDefs[jj]
            }
        }
Ejemplo n.º 6
0
 public SimRuntime(ClusterDef def)
 {
     Def        = def;
     _scheduler = new SimScheduler(this, new ServiceId("simulation:proc"));
     _factory   = new TaskFactory(_scheduler);
 }
Ejemplo n.º 7
0
        // Note: cConstraintsPerVar is an artifact of ProjectionSolver testing and is ignored
        // in OverlapRemoval since we generate only the necessary constraints for removing overlaps (it
        // could be extended to generate additional overlaps but that has not yet been done).
        public bool CreateFile(uint cVars, uint cConstraintsPerVar, string strOutFile)
        {
            Validate.IsTrue(cVars > 0, "Test file creation requires cVars > 0");
            Validate.AreNotEqual((uint)0, cConstraintsPerVar, "Test file creation requires cConstraintsPerVar > 0");

            // Generate a new set of Variable definitions.
            var    lstVarDefs = new List <VariableDef>();
            Random rng        = TestConstraints.NewRng();

            // Print this so that in case of errors we can re-run with this seed.
            Console.WriteLine("Creating test file with seed 0x{0}", TestConstraints.RandomSeed.ToString("X"));

            //
            // This code was adapted from satisfy_inc for ProjSolver, and then the second dimension
            // and sizes were added for OverlapRemoval, as well as other extensions.
            //

            for (int idxVar = 0; idxVar < cVars; ++idxVar)
            {
                double dblPosX = TestConstraints.RoundRand(rng, TestConstraints.MaxNodePosition);
                double dblPosY = TestConstraints.RoundRand(rng, TestConstraints.MaxNodePosition);

                // Ensure nonzero sizes.
                double dblSizeX = TestConstraints.RoundRand(rng, MaxSize) + 1.0;
                double dblSizeY = TestConstraints.RoundRand(rng, MaxSize) + 1.0;

                double dblWeightX = 1.0, dblWeightY = 1.0;
                if (TestConstraints.MaxWeightToGenerate > 0.0)
                {
                    // Ensure nonzero weights.
                    dblWeightX = TestConstraints.RoundRand(rng, TestConstraints.MaxWeightToGenerate) + 0.01;
                    dblWeightY = TestConstraints.RoundRand(rng, TestConstraints.MaxWeightToGenerate) + 0.01;
                }

                lstVarDefs.Add(new VariableDef((uint)idxVar
                                               , dblPosX, dblPosY
                                               , dblSizeX, dblSizeY
                                               , dblWeightX, dblWeightY));
            } // endfor idxVar

            List <ClusterDef> lstClusDefs = null;

            if (MaxClusters > 0)
            {
                // If we are generating a random number of clusters, get that number here.
                int cClusters = MaxClusters;
                if (WantRandomClusters)
                {
                    cClusters = rng.Next(cClusters);
                }

                // Add the first cluster, at the root level - hence no parent and no borders.
                // No BorderInfo needed for root clusters - it's ignored.  RoundRand returns
                // 0 if its arg is 0.
                lstClusDefs = new List <ClusterDef>(cClusters)
                {
                    new ClusterDef(
                        TestConstraints.RoundRand(rng, MinClusterSizeX),
                        TestConstraints.RoundRand(rng, MinClusterSizeY))
                    {
                        IsNewHierarchy = true
                    }
                };
                if (TestGlobals.VerboseLevel >= 3)
                {
                    Console.WriteLine("Level-1 cluster: {0}", lstClusDefs[0].ClusterId);
                }

                // If we are doing a single hierarchy only, restrict the range to the current set of parents,
                // otherwise ourselves about a 10% chance of being at the root level instead of being nested.
                int cRootExtra = WantSingleClusterRoot ? 0 : Math.Max(cClusters / 10, 1);

                // Create the clusters, randomly selecting a parent for each from the items previously
                // put in the list.
                for (int idxNewClus = 1; idxNewClus < cClusters; ++idxNewClus)
                {
                    int idxParentClus = rng.Next(lstClusDefs.Count + cRootExtra);   // Allow out-of-bounds index as "root level" flag

                    // Margin stuff stays 0 if MaxMargin is 0 (and border stuff is ignored if it's a root cluster).
                    var clusNew = new ClusterDef(TestConstraints.RoundRand(rng, MinClusterSizeX), TestConstraints.RoundRand(rng, MinClusterSizeY),
                                                 GetBorderInfo(lstClusDefs.Count, TestConstraints.RoundRand(rng, MaxMargin), WantFixedLeftBorder),
                                                 GetBorderInfo(lstClusDefs.Count, TestConstraints.RoundRand(rng, MaxMargin), WantFixedRightBorder),
                                                 GetBorderInfo(lstClusDefs.Count, TestConstraints.RoundRand(rng, MaxMargin), WantFixedTopBorder),
                                                 GetBorderInfo(lstClusDefs.Count, TestConstraints.RoundRand(rng, MaxMargin), WantFixedBottomBorder));
                    lstClusDefs.Add(clusNew);

                    // If we are doing a single hierarchy only, restrict the range to the current set of parents.
                    // Otherwise, if the parent index is >= the index we're adding now, that's our way of
                    // selecting the node to be at the root level.
                    if (WantSingleClusterRoot)
                    {
                        idxParentClus %= idxNewClus;
                    }
                    if (idxParentClus < idxNewClus)
                    {
                        ClusterDef clusParent = lstClusDefs[idxParentClus];
                        clusParent.AddClusterDef(clusNew);
                        if (TestGlobals.VerboseLevel >= 3)
                        {
                            Console.Write("Nested cluster: {0}", clusNew.ClusterId);
                            for (; null != clusParent; clusParent = clusParent.ParentClusterDef)
                            {
                                Console.Write(" {0}", clusParent.ClusterId);
                            }
                            Console.WriteLine();
                        }
                    }
                    else
                    {
                        // Create a simple cluster since root clusters don't honor borders.
                        clusNew.IsNewHierarchy = true;
                        if (TestGlobals.VerboseLevel >= 3)
                        {
                            Console.WriteLine("Level-1 cluster: {0}", clusNew.ClusterId);
                        }
                    }
                }

                // Now run through the nodes and randomly assign them into the clusters.
                foreach (VariableDef varDef in lstVarDefs)
                {
                    int idxParentClus = rng.Next(lstClusDefs.Count + cRootExtra);
                    if (idxParentClus < lstClusDefs.Count)
                    {                        // Don't write the ones at the root level.
                        lstClusDefs[idxParentClus].AddVariableDef(varDef);
                    }
                    else if (TestGlobals.VerboseLevel >= 3)
                    {
                        Console.WriteLine("Root var: {0}", varDef.IdString);
                    }
                }
            } // endif MaxClusters > 0

            return(WriteTestFile(lstVarDefs, lstClusDefs, strOutFile));
        }
        private ESection ProcessCluster(int lineNumber, string currentLine, ESection currentSection, ref EClusterState currentClusterState)
        {
            if (currentLine.StartsWith(
                TestFileStrings.EndCluster, StringComparison.OrdinalIgnoreCase))
            {
                if (EClusterState.Variable != currentClusterState)
                {
                    Validate.Fail(string.Format("Unexpected END CLUSTER line {0}: {1}", lineNumber, currentLine));
                }
                currentSection = ESection.PreClusterOrConstraints;
                this.ClusterDefs.Add(this.currentClusterDef);
                this.currentClusterDef = null;
                return currentSection;
            }
            if (EClusterState.Id == currentClusterState)
            {
                Match m = TestFileStrings.ParseClusterId.Match(currentLine);
                if (m.Success)
                {
                    // Verify the Clusters in the file are sorted on ID.  This makes it easier for the results
                    // reading to be in sync, as we'll index ClusterDefs by [Parent - 1].
                    var id = int.Parse(m.Groups["id"].ToString());
                    Validate.IsTrue(this.currentClusterDef.ClusterId == id, "Out of order CLUSTER id");
                }
                else
                {
                    Validate.Fail(string.Format("Unparsable CLUSTER ID line {0}: {1}", lineNumber, currentLine));
                }
                currentClusterState = EClusterState.Parent;
            }
            else if (EClusterState.Parent == currentClusterState)
            {
                Match m = TestFileStrings.ParseClusterParent.Match(currentLine);
                if (m.Success)
                {
                    int parentId = int.Parse(m.Groups["parent"].ToString());

                    // Cluster IDs are 1-based because we use 0 for the "root cluster".
                    if (0 != parentId)
                    {
                        ClusterDef clusParent = this.ClusterDefs[parentId - 1];
                        Validate.AreEqual(clusParent.ClusterId, parentId, "clusParent.ClusterId mismatch with idParent");
                        clusParent.AddClusterDef(this.currentClusterDef);
                    }
                }
                else
                {
                    Validate.Fail(string.Format("Unparsable CLUSTER Parent line {0}: {1}", lineNumber, currentLine));
                }
                currentClusterState = EClusterState.LeftBorder;
            }
            else if (EClusterState.LeftBorder == currentClusterState)
            {
                // Older files didn't have MinSize.
                Match m = TestFileStrings.ParseClusterMinSize.Match(currentLine);
                if (m.Success)
                {
                    this.currentClusterDef.MinimumSizeX = double.Parse(m.Groups["X"].ToString());
                    this.currentClusterDef.MinimumSizeY = double.Parse(m.Groups["Y"].ToString());
                    return currentSection;
                }
                if (0 == string.Compare("NewHierarchy", currentLine, StringComparison.OrdinalIgnoreCase))
                {
                    // NewHierarchy is optional.
                    this.currentClusterDef.IsNewHierarchy = true;
                    return currentSection;
                }
                this.currentClusterDef.LeftBorderInfo = ParseBorderInfo("Left", currentLine, lineNumber);
                currentClusterState = EClusterState.RightBorder;
            }
            else if (EClusterState.RightBorder == currentClusterState)
            {
                this.currentClusterDef.RightBorderInfo = ParseBorderInfo("Right", currentLine, lineNumber);
                currentClusterState = EClusterState.TopBorder;
            }
            else if (EClusterState.TopBorder == currentClusterState)
            {
                this.currentClusterDef.TopBorderInfo = ParseBorderInfo("Top", currentLine, lineNumber);
                currentClusterState = EClusterState.BottomBorder;
            }
            else if (EClusterState.BottomBorder == currentClusterState)
            {
                this.currentClusterDef.BottomBorderInfo = ParseBorderInfo("Bottom", currentLine, lineNumber);
                currentClusterState = EClusterState.Variable;
            }
            else if (EClusterState.Variable == currentClusterState)
            {
                Match m = TestFileStrings.ParseClusterVariable.Match(currentLine);
                if (m.Success)
                {
                    int variableId = int.Parse(m.Groups["var"].ToString());
                    this.currentClusterDef.AddVariableDef(this.VariableDefs[variableId]);
                }
                else
                {
                    Validate.Fail(string.Format("Unparsable CLUSTER Variable line {0}: {1}", lineNumber, currentLine));
                }
            }
            return currentSection;
        }
 private ESection ProcessClusterOrConstraints(string currentLine, ESection currentSection, ref EClusterState currentClusterState)
 {
     if (currentLine.StartsWith(
         TestFileStrings.BeginCluster, StringComparison.OrdinalIgnoreCase))
     {
         currentSection = ESection.Cluster;
         currentClusterState = EClusterState.Id;
         this.currentClusterDef = new ClusterDef(this.MinClusterSizeX, this.MinClusterSizeY);
         return currentSection;
     }
     if (currentLine.StartsWith(
         TestFileStrings.BeginConstraintsX, StringComparison.OrdinalIgnoreCase))
     {
         currentSection = ESection.Constraints;
         this.currentConstraintDefs = this.ConstraintDefsX;
         return currentSection;
     }
     if (currentLine.StartsWith(
         TestFileStrings.BeginConstraintsY, StringComparison.OrdinalIgnoreCase))
     {
         currentSection = ESection.Constraints;
         this.currentConstraintDefs = this.ConstraintsDefY;
         return currentSection;
     }
     if (currentLine.StartsWith(
         TestFileStrings.BeginConstraints, StringComparison.OrdinalIgnoreCase))
     {
         currentSection = ESection.Constraints;
         this.currentConstraintDefs = this.ConstraintDefsX;
         return currentSection;
     }
     return currentSection;
 }
        private static void Setup__Test_Cluster_Pad0_Sibling9_Nest1_MinSize(int width, int height, out VariableDef[] variableDefs, out ClusterDef[] clusterDefs)
        {
            variableDefs = new[]
                {
                    //ordinal                  posXY     sizeXY      There is only one cluster, with 'b' vars; 'a' is root
                    /* 0  */ new VariableDef(1.0, 1.0, 3.0, 3.0),
                    /* 1  */ new VariableDef(2.0, 1.0, 3.0, 3.0),
                    /* 2  */ new VariableDef(3.0, 1.0, 3.0, 3.0),

                    /* 3  */ new VariableDef(1.0, 2.0, 3.0, 3.0),
                    /* 4  */ new VariableDef(2.0, 2.0, 3.0, 3.0),
                    /* 5  */ new VariableDef(3.0, 2.0, 3.0, 3.0),

                    /* 6  */ new VariableDef(1.0, 3.0, 3.0, 3.0),
                    /* 7  */ new VariableDef(2.0, 3.0, 3.0, 3.0),
                    /* 8  */ new VariableDef(3.0, 3.0, 3.0, 3.0),
                };

            clusterDefs = new ClusterDef[10];
            clusterDefs[0] = new ClusterDef(); // Parent cluster

            for (int ii = 1; ii <= 9; ++ii)
            {
                // 1-based to skip the parent cluster.
                clusterDefs[ii] = new ClusterDef(width, height);
                clusterDefs[ii].AddVariableDef(variableDefs[ii - 1]); // 0-based
                clusterDefs[0].AddClusterDef(clusterDefs[ii]);
            }
        }
        // Note: cConstraintsPerVar is an artifact of ProjectionSolver testing and is ignored
        // in OverlapRemoval since we generate only the necessary constraints for removing overlaps (it 
        // could be extended to generate additional overlaps but that has not yet been done).
        public bool CreateFile(uint cVars, uint cConstraintsPerVar, string strOutFile)
        {
            Validate.IsTrue(cVars > 0, "Test file creation requires cVars > 0");
            Validate.AreNotEqual((uint)0, cConstraintsPerVar, "Test file creation requires cConstraintsPerVar > 0");

            // Generate a new set of Variable definitions.
            var lstVarDefs = new List<VariableDef>();
            Random rng = TestConstraints.NewRng();

            // Print this so that in case of errors we can re-run with this seed.
            Console.WriteLine("Creating test file with seed 0x{0}", TestConstraints.RandomSeed.ToString("X"));

            //
            // This code was adapted from satisfy_inc for ProjSolver, and then the second dimension
            // and sizes were added for OverlapRemoval, as well as other extensions.
            //

            for (int idxVar = 0; idxVar < cVars; ++idxVar)
            {
                double dblPosX = TestConstraints.RoundRand(rng, TestConstraints.MaxNodePosition);
                double dblPosY = TestConstraints.RoundRand(rng, TestConstraints.MaxNodePosition);

                // Ensure nonzero sizes.
                double dblSizeX = TestConstraints.RoundRand(rng, MaxSize) + 1.0;
                double dblSizeY = TestConstraints.RoundRand(rng, MaxSize) + 1.0;

                double dblWeightX = 1.0, dblWeightY = 1.0;
                if (TestConstraints.MaxWeightToGenerate > 0.0)
                {
                    // Ensure nonzero weights.
                    dblWeightX = TestConstraints.RoundRand(rng, TestConstraints.MaxWeightToGenerate) + 0.01;
                    dblWeightY = TestConstraints.RoundRand(rng, TestConstraints.MaxWeightToGenerate) + 0.01;
                }

                lstVarDefs.Add(new VariableDef((uint)idxVar
                                                , dblPosX, dblPosY
                                                , dblSizeX, dblSizeY
                                                , dblWeightX, dblWeightY));
            } // endfor idxVar

            List<ClusterDef> lstClusDefs = null;
            if (MaxClusters > 0)
            {
                // If we are generating a random number of clusters, get that number here.
                int cClusters = MaxClusters;
                if (WantRandomClusters)
                {
                    cClusters = rng.Next(cClusters);
                }

                // Add the first cluster, at the root level - hence no parent and no borders.
                // No BorderInfo needed for root clusters - it's ignored.  RoundRand returns
                // 0 if its arg is 0.
                lstClusDefs = new List<ClusterDef>(cClusters)
                    {
                        new ClusterDef(
                            TestConstraints.RoundRand(rng, MinClusterSizeX),
                            TestConstraints.RoundRand(rng, MinClusterSizeY))
                            {
                                IsNewHierarchy = true
                            }
                    };
                if (TestGlobals.VerboseLevel >= 3)
                {
                    Console.WriteLine("Level-1 cluster: {0}", lstClusDefs[0].ClusterId);
                }

                // If we are doing a single hierarchy only, restrict the range to the current set of parents,
                // otherwise ourselves about a 10% chance of being at the root level instead of being nested.
                int cRootExtra = WantSingleClusterRoot ? 0 : Math.Max(cClusters / 10, 1);

                // Create the clusters, randomly selecting a parent for each from the items previously
                // put in the list.
                for (int idxNewClus = 1; idxNewClus < cClusters; ++idxNewClus)
                {
                    int idxParentClus = rng.Next(lstClusDefs.Count + cRootExtra);   // Allow out-of-bounds index as "root level" flag

                    // Margin stuff stays 0 if MaxMargin is 0 (and border stuff is ignored if it's a root cluster).
                    var clusNew = new ClusterDef(TestConstraints.RoundRand(rng, MinClusterSizeX), TestConstraints.RoundRand(rng, MinClusterSizeY),
                                               GetBorderInfo(lstClusDefs.Count, TestConstraints.RoundRand(rng, MaxMargin), WantFixedLeftBorder),
                                               GetBorderInfo(lstClusDefs.Count, TestConstraints.RoundRand(rng, MaxMargin), WantFixedRightBorder),
                                               GetBorderInfo(lstClusDefs.Count, TestConstraints.RoundRand(rng, MaxMargin), WantFixedTopBorder),
                                               GetBorderInfo(lstClusDefs.Count, TestConstraints.RoundRand(rng, MaxMargin), WantFixedBottomBorder));
                    lstClusDefs.Add(clusNew);

                    // If we are doing a single hierarchy only, restrict the range to the current set of parents.
                    // Otherwise, if the parent index is >= the index we're adding now, that's our way of
                    // selecting the node to be at the root level.
                    if (WantSingleClusterRoot)
                    {
                        idxParentClus %= idxNewClus;
                    }
                    if (idxParentClus < idxNewClus)
                    {
                        ClusterDef clusParent = lstClusDefs[idxParentClus];
                        clusParent.AddClusterDef(clusNew);
                        if (TestGlobals.VerboseLevel >= 3)
                        {
                            Console.Write("Nested cluster: {0}", clusNew.ClusterId);
                            for (; null != clusParent; clusParent = clusParent.ParentClusterDef)
                            {
                                Console.Write(" {0}", clusParent.ClusterId);
                            }
                            Console.WriteLine();
                        }
                    }
                    else
                    {
                        // Create a simple cluster since root clusters don't honor borders.
                        clusNew.IsNewHierarchy = true;
                        if (TestGlobals.VerboseLevel >= 3)
                        {
                            Console.WriteLine("Level-1 cluster: {0}", clusNew.ClusterId);
                        }
                    }
                }

                // Now run through the nodes and randomly assign them into the clusters.
                foreach (VariableDef varDef in lstVarDefs)
                {
                    int idxParentClus = rng.Next(lstClusDefs.Count + cRootExtra);
                    if (idxParentClus < lstClusDefs.Count)
                    {                        // Don't write the ones at the root level.
                        lstClusDefs[idxParentClus].AddVariableDef(varDef);
                    }
                    else if (TestGlobals.VerboseLevel >= 3)
                    {
                        Console.WriteLine("Root var: {0}", varDef.IdString);
                    }
                }
            } // endif MaxClusters > 0

            return WriteTestFile(lstVarDefs, lstClusDefs, strOutFile);
        }