public override bool Mutate(Individual individual)
{
SyntaxTree tree = (SyntaxTree)individual.SyntaxTree.DeepClone();
TreeNode exchangeNode = tree.GetRandomNode();
Type nodeType = exchangeNode.Type;
TreeNode newNode = SyntaxTreeProvider.GetSyntaxTree(MaxMutationTreeDepth, nodeType);
if (newNode != null)
{
bool replaced = tree.ReplaceTreeNode(exchangeNode, newNode);
if (replaced && tree.Height <= MaxTreeDepth)
{
individual.SyntaxTree = tree;
return(true);
}
}
return(false);
}
public override bool Mutate(Individual individual)
{
SyntaxTree tree = (SyntaxTree)individual.SyntaxTree.DeepClone();
TreeNode exchangeNode = tree.GetRandomNode();
Type nodeType = exchangeNode.Type;
TreeNode newNode = SyntaxTreeProvider.GetSyntaxTree(MaxMutationTreeDepth, nodeType);
if (newNode != null)
{
bool replaced = tree.ReplaceTreeNode(exchangeNode, (TreeNode)newNode.DeepClone());
if (replaced && tree.Height <= MaxTreeDepth)
{
individual.SyntaxTree = tree;
if (individual.FitnessEvaluated) // only meaningful if fitness of individual is already evaluated
// update the node's record
{
var recordSubTreePool = SyntaxTreeProvider as RecordBasedSubTreePool;
double improvement = 0;
if (FitnessEvaluator != null)
{
var fitness = FitnessEvaluator.Evaluate(individual, Problem).Fitness;
improvement = fitness - individual.Fitness;
Statistics.Instance.AddRecordReplaceAttempt(improvement);
}
if (recordSubTreePool != null)
{
recordSubTreePool.UpdateRecord(newNode, improvement);
}
}
return(true);
}
}
return(false);
}
