예제 #1
0
        public IEnumerable <TLayout> Evolve(TLayout initialLayout, Chain <TNode> chain, int count)
        {
            for (int i = 0; i < count; i++)
            {
                var copy = initialLayout.SmartClone();
                layoutOperations.AddChain(copy, chain.Nodes, true, out var iterationsCount);

                foreach (var _ in chain.Nodes)
                {
                    OnPerturbed?.Invoke(this, copy);
                }

                if (layoutOperations.IsLayoutValid(copy))
                {
                    // TODO: why chain.Nodes instead of chain?
                    if (layoutOperations.TryCompleteChain(copy, chain.Nodes))
                    {
                        yield return(copy);
                    }
                }
            }
        }
        /// <inheritdoc />
        public IEnumerable <TLayout> Evolve(TLayout initialLayout, Chain <TNode> chain, int count)
        {
            var configuration = GetConfiguration(chain.Number);

            if (!chain.IsFromFace && configuration.HandleTreesGreedily)
            {
                var iters          = 0;
                var lastEventIters = 0;

                for (int i = 0; i < 2; i++)
                {
                    if (CancellationToken.HasValue && CancellationToken.Value.IsCancellationRequested)
                    {
                        yield break;
                    }

                    for (int k = 0; k < 1; k++)
                    {
                        if (CancellationToken.HasValue && CancellationToken.Value.IsCancellationRequested)
                        {
                            yield break;
                        }

                        var copy = initialLayout.SmartClone();
                        LayoutOperations.AddChain(copy, chain.Nodes, true, out var addChainIterationsCount);

                        iters += addChainIterationsCount;

                        // An event must be sent in order for the early stopping handler to work
                        OnPerturbed?.Invoke(this, copy);

                        if (CancellationToken.HasValue && CancellationToken.Value.IsCancellationRequested)
                        {
                            yield break;
                        }

                        if (LayoutOperations.IsLayoutValid(copy))
                        {
                            if (LayoutOperations.TryCompleteChain(copy, chain.Nodes))
                            {
                                OnPerturbed?.Invoke(this, copy);

                                if (CancellationToken.HasValue && CancellationToken.Value.IsCancellationRequested)
                                {
                                    yield break;
                                }

                                OnEvent?.Invoke(this, new SimulatedAnnealingEventArgs()
                                {
                                    Type = SimulatedAnnealingEventType.LayoutGenerated,
                                    IterationsSinceLastEvent = iters - lastEventIters,
                                    IterationsTotal          = iters,
                                    LayoutsGenerated         = -1,
                                    ChainNumber = chain.Number,
                                });

                                lastEventIters = iters;

                                yield return(copy);

                                break;
                            }
                        }

                        OnEvent?.Invoke(this, new SimulatedAnnealingEventArgs()
                        {
                            Type = SimulatedAnnealingEventType.OutOfIterations,
                            IterationsSinceLastEvent = iters - lastEventIters,
                            IterationsTotal          = iters,
                            LayoutsGenerated         = -1,
                            ChainNumber = chain.Number,
                        });

                        lastEventIters = iters;
                    }
                }

                yield break;
            }

            if (addNodesGreedilyBeforeEvolve)
            {
                LayoutOperations.AddChain(initialLayout, chain.Nodes, true, out var addChainIterationsCount);
            }

            const double p0                = 0.2d;
            const double p1                = 0.01d;
            var          t0                = -1d / Math.Log(p0);
            var          t1                = -1d / Math.Log(p1);
            var          ratio             = Math.Pow(t1 / t0, 1d / (configuration.Cycles - 1));
            var          deltaEAvg         = 0d;
            var          acceptedSolutions = 1;

            var t = t0;

            var layouts        = new List <TLayout>();
            var originalLayout = initialLayout;
            var currentLayout  = originalLayout;

            #region Debug output

            //if (withDebugOutput)
            //{
            //	Console.WriteLine($"Initial energy: {layoutOperations.GetEnergy(currentLayout)}");
            //}

            #endregion

            var numberOfFailures = 0;
            var stageTwoFailures = 0;

            var iterations          = 0;
            var lastEventIterations = 0;

            var shouldStop = false;

            for (var i = 0; i < configuration.Cycles; i++)
            {
                var wasAccepted = false;

                #region Random restarts

                if (enableRandomRestarts)
                {
                    if (ShouldRestart(numberOfFailures))
                    {
                        OnEvent?.Invoke(this, new SimulatedAnnealingEventArgs()
                        {
                            Type = SimulatedAnnealingEventType.RandomRestart,
                            IterationsSinceLastEvent = iterations - lastEventIterations,
                            IterationsTotal          = iterations,
                            LayoutsGenerated         = layouts.Count,
                            ChainNumber = chain.Number,
                        });
                        yield break;
                    }
                }

                #endregion

                if (iterations - lastEventIterations > configuration.MaxIterationsWithoutSuccess)
                {
                    break;
                }

                if (shouldStop)
                {
                    break;
                }

                for (var j = 0; j < configuration.TrialsPerCycle; j++)
                {
                    if (CancellationToken.HasValue && CancellationToken.Value.IsCancellationRequested)
                    {
                        yield break;
                    }

                    if (stageTwoFailures > configuration.MaxStageTwoFailures)
                    {
                        shouldStop = true;
                        break;
                    }

                    iterations++;
                    var perturbedLayout = PerturbLayout(currentLayout, chain.Nodes, out var energyDelta);

                    OnPerturbed?.Invoke(this, perturbedLayout);

                    // TODO: can we check the energy instead?
                    if (LayoutOperations.IsLayoutValid(perturbedLayout, chain.Nodes))
                    {
                        #region Random restarts
                        if (enableRandomRestarts && randomRestartsSuccessPlace == RestartSuccessPlace.OnValid)
                        {
                            wasAccepted = true;

                            if (randomRestartsResetCounter)
                            {
                                numberOfFailures = 0;
                            }
                        }
                        #endregion

                        // TODO: wouldn't it be too slow to compare againts all?
                        if (IsDifferentEnough(perturbedLayout, layouts))
                        {
                            // TODO 2SG: should we clone before TryCompleteChain or should TryCompleteChain not change the layout?
                            var newLayout      = perturbedLayout.SmartClone();
                            var shouldContinue = LayoutOperations.TryCompleteChain(newLayout, chain.Nodes);

                            if (shouldContinue)
                            {
                                layouts.Add(newLayout);
                                OnValid?.Invoke(this, newLayout);

                                #region Random restarts
                                if (enableRandomRestarts && randomRestartsSuccessPlace == RestartSuccessPlace.OnValidAndDifferent)
                                {
                                    wasAccepted = true;

                                    if (randomRestartsResetCounter)
                                    {
                                        numberOfFailures = 0;
                                    }
                                }
                                #endregion

                                OnEvent?.Invoke(this, new SimulatedAnnealingEventArgs()
                                {
                                    Type = SimulatedAnnealingEventType.LayoutGenerated,
                                    IterationsSinceLastEvent = iterations - lastEventIterations,
                                    IterationsTotal          = iterations,
                                    LayoutsGenerated         = layouts.Count,
                                    ChainNumber = chain.Number,
                                });

                                yield return(newLayout);

                                lastEventIterations = iterations;
                                stageTwoFailures    = 0;

                                #region Debug output

                                //if (withDebugOutput)
                                //{
                                //	Console.WriteLine($"Found layout, cycle {i}, trial {j}, energy {layoutOperations.GetEnergy(perturbedLayout)}");
                                //}

                                #endregion

                                if (layouts.Count >= count)
                                {
                                    #region Debug output

                                    //if (withDebugOutput)
                                    //{
                                    //	Console.WriteLine($"Returning {layouts.Count} partial layouts");
                                    //}

                                    #endregion

                                    yield break;
                                }
                            }
                            else
                            {
                                stageTwoFailures++;

                                OnEvent?.Invoke(this, new SimulatedAnnealingEventArgs()
                                {
                                    Type = SimulatedAnnealingEventType.StageTwoFailure,
                                    IterationsSinceLastEvent = iterations - lastEventIterations,
                                    IterationsTotal          = iterations,
                                    LayoutsGenerated         = layouts.Count,
                                    ChainNumber = chain.Number,
                                    ResetsIterationsSinceLastEvent = false,
                                });
                            }
                        }
                    }

                    var deltaAbs = Math.Abs(energyDelta);
                    var accept   = false;

                    if (energyDelta > 0)
                    {
                        if (i == 0 && j == 0)
                        {
                            deltaEAvg = deltaAbs * 15;
                        }

                        var p = Math.Pow(Math.E, -deltaAbs / (deltaEAvg * t));
                        if (Random.NextDouble() < p)
                        {
                            accept = true;
                        }
                    }
                    else
                    {
                        accept = true;
                    }

                    if (accept)
                    {
                        acceptedSolutions++;
                        currentLayout = perturbedLayout;
                        deltaEAvg     = (deltaEAvg * (acceptedSolutions - 1) + deltaAbs) / acceptedSolutions;

                        #region Random restarts
                        if (enableRandomRestarts && randomRestartsSuccessPlace == RestartSuccessPlace.OnAccepted)
                        {
                            wasAccepted = true;

                            if (randomRestartsResetCounter)
                            {
                                numberOfFailures = 0;
                            }
                        }
                        #endregion
                    }
                }

                if (!wasAccepted)
                {
                    numberOfFailures++;
                }

                t = t * ratio;
            }

            OnEvent?.Invoke(this, new SimulatedAnnealingEventArgs()
            {
                Type = SimulatedAnnealingEventType.OutOfIterations,
                IterationsSinceLastEvent = iterations - lastEventIterations,
                IterationsTotal          = iterations,
                LayoutsGenerated         = layouts.Count,
                ChainNumber = chain.Number,
            });
        }
예제 #3
0
        /// <inheritdoc />
        public IEnumerable <TLayout> Evolve(TLayout initialLayout, IList <TNode> chain, int count)
        {
            const double p0                = 0.2d;
            const double p1                = 0.01d;
            var          t0                = -1d / Math.Log(p0);
            var          t1                = -1d / Math.Log(p1);
            var          ratio             = Math.Pow(t1 / t0, 1d / (Cycles - 1));
            var          deltaEAvg         = 0d;
            var          acceptedSolutions = 1;

            var t = t0;

            var layouts        = new List <TLayout>();
            var originalLayout = initialLayout;
            var currentLayout  = originalLayout;

            #region Debug output

            //if (withDebugOutput)
            //{
            //	Console.WriteLine($"Initial energy: {layoutOperations.GetEnergy(currentLayout)}");
            //}

            #endregion

            var numberOfFailures = 0;

            for (var i = 0; i < Cycles; i++)
            {
                var wasAccepted = false;

                #region Random restarts

                if (enableRandomRestarts)
                {
                    if (ShouldRestart(numberOfFailures))
                    {
                        break;
                    }
                }

                #endregion

                for (var j = 0; j < TrialsPerCycle; j++)
                {
                    if (CancellationToken.HasValue && CancellationToken.Value.IsCancellationRequested)
                    {
                        yield break;
                    }

                    var perturbedLayout = PerturbLayout(currentLayout, chain, out var energyDelta);

                    OnPerturbed?.Invoke(perturbedLayout);

                    // TODO: can we check the energy instead?
                    if (LayoutOperations.IsLayoutValid(perturbedLayout, chain))
                    {
                        #region Random restarts
                        if (enableRandomRestarts && randomRestartsSuccessPlace == RestartSuccessPlace.OnValid)
                        {
                            wasAccepted = true;

                            if (randomRestartsResetCounter)
                            {
                                numberOfFailures = 0;
                            }
                        }
                        #endregion

                        // TODO: wouldn't it be too slow to compare againts all?
                        if (IsDifferentEnough(perturbedLayout, layouts))
                        {
                            var shouldContinue = true;

                            // TODO: should it be like this?
                            if (LayoutOperations is ILayoutOperationsWithCorridors <TLayout, TNode> layoutOperationsWithCorridors)
                            {
                                shouldContinue = layoutOperationsWithCorridors.AddCorridors(perturbedLayout, chain);
                            }

                            if (shouldContinue)
                            {
                                layouts.Add(perturbedLayout);
                                OnValid?.Invoke(perturbedLayout);

                                #region Random restarts
                                if (enableRandomRestarts && randomRestartsSuccessPlace == RestartSuccessPlace.OnValidAndDifferent)
                                {
                                    wasAccepted = true;

                                    if (randomRestartsResetCounter)
                                    {
                                        numberOfFailures = 0;
                                    }
                                }
                                #endregion

                                yield return(perturbedLayout);

                                #region Debug output

                                //if (withDebugOutput)
                                //{
                                //	Console.WriteLine($"Found layout, cycle {i}, trial {j}, energy {layoutOperations.GetEnergy(perturbedLayout)}");
                                //}

                                #endregion

                                if (layouts.Count >= count)
                                {
                                    #region Debug output

                                    //if (withDebugOutput)
                                    //{
                                    //	Console.WriteLine($"Returning {layouts.Count} partial layouts");
                                    //}

                                    #endregion

                                    yield break;
                                }
                            }
                        }
                    }

                    var deltaAbs = Math.Abs(energyDelta);
                    var accept   = false;

                    if (energyDelta > 0)
                    {
                        if (i == 0 && j == 0)
                        {
                            deltaEAvg = deltaAbs * 15;
                        }

                        var p = Math.Pow(Math.E, -deltaAbs / (deltaEAvg * t));
                        if (Random.NextDouble() < p)
                        {
                            accept = true;
                        }
                    }
                    else
                    {
                        accept = true;
                    }

                    if (accept)
                    {
                        acceptedSolutions++;
                        currentLayout = perturbedLayout;
                        deltaEAvg     = (deltaEAvg * (acceptedSolutions - 1) + deltaAbs) / acceptedSolutions;

                        #region Random restarts
                        if (enableRandomRestarts && randomRestartsSuccessPlace == RestartSuccessPlace.OnAccepted)
                        {
                            wasAccepted = true;

                            if (randomRestartsResetCounter)
                            {
                                numberOfFailures = 0;
                            }
                        }
                        #endregion
                    }
                }

                if (!wasAccepted)
                {
                    numberOfFailures++;
                }

                t = t * ratio;
            }
        }