public static IEnumerable<ISymbolicExpressionTreeNode> FindMatches(ISymbolicExpressionTreeNode root, ISymbolicExpressionTreeNode subtree, SymbolicExpressionTreeNodeEqualityComparer comp) {
var fragmentLength = subtree.GetLength();
// below, we use ">=" for Match(n, subtree, comp) >= fragmentLength because in case of relaxed conditions,
// we can have multiple matches of the same node
return root.IterateNodesBreadth().Where(n => n.GetLength() >= fragmentLength && Match(n, subtree, comp) == fragmentLength);
}
public GraphNode(ISymbolicExpressionTreeNode node, string label)
{
SymbolicExpressionTreeNode = node;
Label = label;
Hash = GetHashCode();
Depth = node.GetDepth();
Length = node.GetLength();
}
public static IEnumerable <ISymbolicExpressionTreeNode> FindMatches(ISymbolicExpressionTreeNode root, ISymbolicExpressionTreeNode subtree, SymbolicExpressionTreeNodeEqualityComparer comp)
{
var fragmentLength = subtree.GetLength();
// below, we use ">=" for Match(n, subtree, comp) >= fragmentLength because in case of relaxed conditions,
// we can have multiple matches of the same node
return(root.IterateNodesBreadth().Where(n => n.GetLength() >= fragmentLength && Match(n, subtree, comp) == fragmentLength));
}
public static void PTC2(IRandom random, ISymbolicExpressionTreeNode seedNode,
int maxLength, int maxDepth)
{
// make sure it is possible to create a trees smaller than maxLength and maxDepth
if (seedNode.Grammar.GetMinimumExpressionLength(seedNode.Symbol) > maxLength)
{
throw new ArgumentException("Cannot create trees of length " + maxLength + " or shorter because of grammar constraints.", "maxLength");
}
if (seedNode.Grammar.GetMinimumExpressionDepth(seedNode.Symbol) > maxDepth)
{
throw new ArgumentException("Cannot create trees of depth " + maxDepth + " or smaller because of grammar constraints.", "maxDepth");
}
// tree length is limited by the grammar and by the explicit size constraints
int allowedMinLength = seedNode.Grammar.GetMinimumExpressionLength(seedNode.Symbol);
int allowedMaxLength = Math.Min(maxLength, seedNode.Grammar.GetMaximumExpressionLength(seedNode.Symbol, maxDepth));
int tries = 0;
while (tries++ < MAX_TRIES)
{
// select a target tree length uniformly in the possible range (as determined by explicit limits and limits of the grammar)
int targetTreeLength;
targetTreeLength = random.Next(allowedMinLength, allowedMaxLength + 1);
if (targetTreeLength <= 1 || maxDepth <= 1)
{
return;
}
bool success = TryCreateFullTreeFromSeed(random, seedNode, targetTreeLength - 1, maxDepth - 1);
// if successful => check constraints and return the tree if everything looks ok
if (success && seedNode.GetLength() <= maxLength && seedNode.GetDepth() <= maxDepth)
{
return;
}
else
{
// clean seedNode
while (seedNode.Subtrees.Any())
{
seedNode.RemoveSubtree(0);
}
}
// try a different length MAX_TRIES times
}
throw new ArgumentException("Couldn't create a random valid tree.");
}
public static Tuple <string, int, int, int> CalculateGeneticMaterialChange(ISymbolicExpressionTree child, ItemArray <ISymbolicExpressionTree> parents)
{
Tuple <ISymbolicExpressionTreeNode, int> crossoverPoint = FindCrossoverPoint(child, parents[0]);
if (crossoverPoint == null)
{
return(new Tuple <string, int, int, int>(NOCHANGE, 0, 0, 0));
}
ISymbolicExpressionTreeNode crossoverPointNode = crossoverPoint.Item1;
//may be needed to check difference to parent subtree, otherwise delete
//int indexOfCrossoverPoint = child.Root.IterateNodesBreadth().ToList().IndexOf(crossoverPointNode);
//var parentSubtree = parents[0].Root.IterateNodesBreadth().ToList()[indexOfCrossoverPoint];
return(new Tuple <string, int, int, int>(crossoverPointNode.Symbol.Name, crossoverPointNode.GetDepth(), crossoverPointNode.GetLength(), crossoverPoint.Item2));
}
public static void PTC2(IRandom random, ISymbolicExpressionTreeNode seedNode,
int maxLength, int maxDepth) {
// make sure it is possible to create a trees smaller than maxLength and maxDepth
if (seedNode.Grammar.GetMinimumExpressionLength(seedNode.Symbol) > maxLength)
throw new ArgumentException("Cannot create trees of length " + maxLength + " or shorter because of grammar constraints.", "maxLength");
if (seedNode.Grammar.GetMinimumExpressionDepth(seedNode.Symbol) > maxDepth)
throw new ArgumentException("Cannot create trees of depth " + maxDepth + " or smaller because of grammar constraints.", "maxDepth");
// tree length is limited by the grammar and by the explicit size constraints
int allowedMinLength = seedNode.Grammar.GetMinimumExpressionLength(seedNode.Symbol);
int allowedMaxLength = Math.Min(maxLength, seedNode.Grammar.GetMaximumExpressionLength(seedNode.Symbol, maxDepth));
int tries = 0;
while (tries++ < MAX_TRIES) {
// select a target tree length uniformly in the possible range (as determined by explicit limits and limits of the grammar)
int targetTreeLength;
targetTreeLength = random.Next(allowedMinLength, allowedMaxLength + 1);
if (targetTreeLength <= 1 || maxDepth <= 1) return;
bool success = TryCreateFullTreeFromSeed(random, seedNode, targetTreeLength - 1, maxDepth - 1);
// if successful => check constraints and return the tree if everything looks ok
if (success && seedNode.GetLength() <= maxLength && seedNode.GetDepth() <= maxDepth) {
return;
} else {
// clean seedNode
while (seedNode.Subtrees.Any()) seedNode.RemoveSubtree(0);
}
// try a different length MAX_TRIES times
}
throw new ArgumentException("Couldn't create a random valid tree.");
}
