private bool EvaluateOperator(object left, object right, IOperator op)
{
var leftResult = _compileResultFactory.Create(left);
var rightResult = _compileResultFactory.Create(right);
var result = op.Apply(leftResult, rightResult);
if (result.DataType != DataType.Boolean)
{
throw new ArgumentException("Illegal operator in expression");
}
return((bool)result.Result);
}
/// <summary>
/// Apply the operator until no more improvements can be found.
/// </summary>
/// <returns></returns>
public static bool ApplyUntil <TWeight, TProblem, TObjective, TSolution, TFitness>(this IOperator <TWeight, TProblem, TObjective, TSolution, TFitness> oper,
TProblem problem, TObjective objective, TSolution solution, out TFitness delta)
where TObjective : ObjectiveBase <TProblem, TSolution, TFitness>
where TWeight : struct
{
delta = objective.Zero;
var localDelta = delta;
while (oper.Apply(problem, objective, solution, out localDelta))
{
delta = objective.Add(problem, delta, localDelta);
}
return(!objective.IsZero(problem, delta));
}
public GameResults Generate(int current)
{
var randomNumber = numberGenerator.Generate();
var correctResult = mathOperator.Apply(current, randomNumber);
var correct = new GameResult(correctResult);
var results = new List <GameResult> {
correct
};
for (var i = 0; i < quantity - 1; i++)
{
var incorrectResult = Random.Range(correctResult + 2, correctResult + 10);
results.Add(new GameResult(incorrectResult));
}
return(new GameResults(mathOperator, results, current, randomNumber));
}
/// <summary>
/// Applies the specified operator to the specified search node.
/// </summary>
/// <param name="node">Search node.</param>
/// <param name="oper">Operator to be applied.</param>
/// <returns>New search node.</returns>
protected ISearchNode Apply(ISearchNode node, IOperator oper)
{
switch (SearchType)
{
case SearchType.Forward:
return(oper.Apply((IState)node));
case SearchType.BackwardWithConditions:
return(oper.ApplyBackwards((IConditions)node));
case SearchType.BackwardWithStates:
return(oper.ApplyBackwards((IRelativeState)node).First());
default:
throw new NotSupportedException("Unknown search type!");
}
}
/// <summary>
/// Applies this operation.
/// </summary>param>
/// <returns></returns>
public bool Apply(TProblem problem, TObjective objective, TSolution solution, out TFitness delta)
{
var best = solution;
var bestFitness = objective.Calculate(problem, solution);
delta = objective.Zero;
var success = false;
for (var i = 0; i < _n; i++)
{
TFitness localDelta;
if (_operator.Apply(problem, objective, solution, out localDelta))
{
delta = objective.Add(problem, delta, localDelta);
bestFitness = objective.Subtract(problem, bestFitness, localDelta);
success = true;
}
else if (_stopAtFail)
{ // stop at first fail.
break;
}
}
return(success);
}
private bool EvaluateOperator(object left, object right, IOperator op)
{
var leftResult = _compileResultFactory.Create(left);
var rightResult = _compileResultFactory.Create(right);
var result = op.Apply(leftResult, rightResult);
if (result.DataType != DataType.Boolean)
{
throw new ArgumentException("Illegal operator in expression");
}
return (bool)result.Result;
}
/// <summary>
/// Solves the given problem.
/// </summary>
/// <returns></returns>
public override TSolution Solve(TProblem problem, TObjective objective, out TFitness fitness)
{
var zero = objective.Zero;
_log.Log(Logging.TraceEventType.Information, "Started generating initial solution...");
TFitness globalBestFitness;
var globalBest = _generator.Solve(problem, objective, out globalBestFitness);
_log.Log(Logging.TraceEventType.Information, "Initial solution generated: {0}.", globalBestFitness);
// report new solution.
this.ReportIntermidiateResult(globalBest);
var difference = objective.Zero;
if (_localSearch.Apply(problem, objective, globalBest, out difference))
{ // localsearch leads to better solution, adjust the fitness.
globalBestFitness = objective.Subtract(problem, globalBestFitness, difference);
_log.Log(Logging.TraceEventType.Information, "Improvement found by local search: {0}.", globalBestFitness);
// report new solution.
this.ReportIntermidiateResult(globalBest);
}
var i = 0;
var level = 1;
while (!this.IsStopped &&
(_stopCondition == null || !_stopCondition.Invoke(i, level, problem, objective, globalBest)))
{ // keep running until stop condition is true or this solver is stopped.
// shake things up a bit, or in other word change neighbourhood.
var perturbedSolution = (TSolution)globalBest.Clone();
var perturbedDifference = objective.Zero;
_perturber.Apply(problem, objective, perturbedSolution, level, out perturbedDifference);
// improve things by using a local search procedure.
var localSearchDifference = objective.Zero;
_localSearch.ApplyUntil(problem, objective, perturbedSolution, out localSearchDifference);
// calculate new fitness and compare.
TFitness newFitness = default(TFitness);
if (!objective.IsNonContinuous)
{ // solution fitness can be updated by adding the differences.
newFitness = objective.Add(problem, globalBestFitness, perturbedDifference);
newFitness = objective.Add(problem, newFitness, localSearchDifference);
}
else
{ // solution fitness needs to updated every time.
newFitness = objective.Calculate(problem, perturbedSolution);
}
if (objective.IsBetterThan(problem, newFitness, globalBestFitness))
{ // there was an improvement, keep new solution as global.
globalBestFitness = newFitness;
globalBest = perturbedSolution;
level = 1; // reset level.
_log.Log(Logging.TraceEventType.Information, "Improvement found by perturber and local search: {0}.", globalBestFitness);
// report new solution.
this.ReportIntermidiateResult(globalBest);
}
else
{
level = level + 1;
}
}
_log.Log(Logging.TraceEventType.Information, "Stop condition reached, best: {0}.", globalBestFitness);
fitness = globalBestFitness;
return(globalBest);
}
private void ApplyOperator3(Node expr)
{
mExpression3 = mOperator3.Apply(mExpression3, expr);
mOperator3 = null;
}
private void ApplyOperator2(Node expr)
{
mExpression2 = mOperator2.Apply(mExpression2, expr);
mOperator2 = null;
mExpression3 = null;
}
private void ApplyOperator1(Node expr)
{
mExpression1 = mOperator1.Apply(mExpression1, expr);
mOperator1 = null;
mExpression2 = null;
}
/// <summary>
/// Builds the relaxed planning graph and computes the FF heuristic value.
/// </summary>
/// <param name="state">Starting state.</param>
/// <param name="goalConditions">Goal conditions.</param>
/// <returns>FF cost heuristic value from the specified state.</returns>
private double ComputeFFCost(IState state, IConditions goalConditions)
{
// build an explicit relaxed planning graph
StateLayers.Clear();
ActionLayers.Clear();
StateLayers.Add(CreateFFStateLayer(state.GetRelaxedState()));
while (true)
{
// check goal conditions
IStateLayer stateLayer = StateLayers[StateLayers.Count - 1];
if (goalConditions.Evaluate(stateLayer.GetState()))
{
ActionLayers.Add(new ActionLayer {
CreateFFGoalActionNode(goalConditions, stateLayer.GetState())
});
break;
}
// build new action layer and the next state layer
ActionLayer actionLayer = new ActionLayer();
IState newState = stateLayer.GetState().Clone();
foreach (var successor in RelaxedProblem.GetSuccessors(stateLayer.GetState()))
{
IOperator appliedOperator = successor.GetAppliedOperator();
actionLayer.Add(CreateFFActionNode(appliedOperator, stateLayer.GetState()));
newState = appliedOperator.Apply(newState, true);
}
ActionLayers.Add(actionLayer);
StateLayers.Add(CreateFFStateLayer(newState));
}
// compute FF value
UnsatisfiedOnCurrentLayer.Clear();
UnsatisfiedOnNextLayer.Clear();
MarkedActionNodes.Clear();
var goalNode = ActionLayers[ActionLayers.Count - 1][0];
foreach (var proposition in goalNode.Predecessors)
{
UnsatisfiedOnCurrentLayer.Push(proposition);
}
for (int i = StateLayers.Count - 1; i > 0; --i)
{
IStateLayer nextStateLayer = StateLayers[i - 1];
ActionLayer currentActionLayer = ActionLayers[i - 1];
while (UnsatisfiedOnCurrentLayer.Count != 0)
{
IProposition proposition = UnsatisfiedOnCurrentLayer.Pop();
// 1.) try to satisfy the proposition by an idle arc to the next state layer
if (nextStateLayer.HasProposition(proposition))
{
UnsatisfiedOnNextLayer.Push(proposition);
continue;
}
// 2.) try to satisfy the proposition by a support action node
ActionNode relevantActionNode = GetBestRelevantActionNodeFF(proposition, currentActionLayer);
if (relevantActionNode != null)
{
MarkedActionNodes.Add(relevantActionNode.Operator);
foreach (var prevProposition in relevantActionNode.Predecessors)
{
UnsatisfiedOnNextLayer.Push(prevProposition);
}
}
}
UnsatisfiedSwapper = UnsatisfiedOnNextLayer;
UnsatisfiedOnNextLayer = UnsatisfiedOnCurrentLayer;
UnsatisfiedOnCurrentLayer = UnsatisfiedSwapper;
UnsatisfiedOnNextLayer.Clear();
}
// the result value is a sum of costs of marked action nodes
double result = 0;
foreach (var markedActionNode in MarkedActionNodes)
{
result += markedActionNode.GetCost();
}
return(result);
}
private void ApplyOperator2(Expression expr)
{
_expression2 = _operator2.Apply(_expression2, expr);
_operator2 = null;
_expression3 = null;
}
private void ApplyOperator1(Expression expr)
{
_expression1 = _operator1.Apply(_expression1, expr);
_operator1 = null;
_expression2 = null;
}
public void Visit(IOperator visitee)
{
visitee.Apply();
Console.WriteLine(visitee.GetValue());
value = int.Parse(visitee.GetValue());
}
public static BasicExpression Apply(IOperator op, BasicExpression x, BasicExpression y)
{
return(op.Apply(x, y));
}
/// <summary>
/// Solves the given problem.
/// </summary>
/// <returns></returns>
public override TSolution Solve(TProblem problem, TObjective objective, out TFitness fitness)
{
var population = new Individual <TSolution, TFitness> [_settings.PopulationSize];
// generate initial population.
var solutionCount = 0;
while (solutionCount < _settings.PopulationSize)
{
TFitness localFitness;
var solution = _generator.Solve(problem, objective, out localFitness);
population[solutionCount] = new Individual <TSolution, TFitness>()
{
Fitness = localFitness,
Solution = solution
};
solutionCount++;
}
// sort population.
Array.Sort(population, (x, y) =>
{
return(objective.CompareTo(problem, x.Fitness, y.Fitness));
});
var bestIndividual = population[0];
this.ReportIntermidiateResult(bestIndividual.Solution);
// mutate/crossover population.
var stagnation = 0;
var generation = 0;
var elitism = (int)(_settings.PopulationSize * (_settings.ElitismPercentage / 100.0));
var crossOver = (int)(_settings.PopulationSize * (_settings.CrossOverPercentage / 100.0));
var crossOverIndividuals = new Individual <TSolution, TFitness> [crossOver];
var exclude = new HashSet <int>();
while (stagnation < _settings.StagnationCount &&
generation < _settings.MaxGenerations &&
!this.IsStopped)
{
// select individuals for crossover.
exclude.Clear();
for (int i = 0; i < crossOver; i++)
{
// select individual.
var selected = -1;
while (selected < 0)
{
selected = _selection.Select(problem, objective, population, exclude);
}
crossOverIndividuals[i] = population[selected];
exclude.Add(selected);
}
// replace part of the population by offspring.
for (int i = elitism; i < population.Length; i++)
{
// take two random parents.
var individual1 = _random.Next(crossOver);
var individual2 = _random.Next(crossOver - 1);
if (individual1 <= individual2)
{ // make sure they are different.
individual2++;
}
// create offspring.
TFitness offspringFitness;
var offspring = _crossOver.Apply(problem, objective, population[individual1].Solution,
population[individual2].Solution, out offspringFitness);
population[i] = new Individual <TSolution, TFitness>()
{
Solution = offspring,
Fitness = offspringFitness
};
}
// mutate part of the population.
for (int i = elitism; i < population.Length; i++)
{
if (_random.Next(100) <= _settings.MutationPercentage)
{ // ok, mutate this individual.
TFitness mutatedDelta;
if (_mutation.Apply(problem, objective, population[i].Solution, out mutatedDelta))
{ // mutation succeeded.
population[i].Fitness = objective.Subtract(problem, population[i].Fitness, mutatedDelta);
}
}
}
// sort new population.
Array.Sort(population, (x, y) =>
{
return(objective.CompareTo(problem, x.Fitness, y.Fitness));
});
if (objective.IsBetterThan(problem, bestIndividual.Fitness, population[0].Fitness))
{ // a better individual was found.
bestIndividual = population[0];
stagnation = 0; // reset stagnation flag.
this.ReportIntermidiateResult(bestIndividual.Solution);
}
else
{ // no better solution found.
stagnation++;
}
}
fitness = bestIndividual.Fitness;
return(bestIndividual.Solution);
}
/// <summary>
/// Returns true if there was an improvement, false otherwise.
/// </summary>
/// <param name="problem">The problem.</param>
/// <param name="objective">The objective.</param>
/// <param name="solution">The solution.</param>
/// <param name="delta">The difference in fitness, when > 0 there was an improvement and a reduction in fitness.</param>
/// <returns></returns>
public bool Apply(TProblem problem, TObjective objective, TSolution solution, out TFitness delta)
{
return(_operator.Apply(problem, objective, solution, out delta));
}
private void ApplyOperator3(Expression expr)
{
_expression3 = _operator3.Apply(_expression3, expr);
_operator3 = null;
}