/// <summary>
/// Looks for the child that gets activated for the given value.
/// </summary>
/// <param name="value">The value to find the fitting child for.</param>
/// <param name="child">Outputs the child if one was found, else null.</param>
/// <exception cref="ArgumentException">Thrown if the given value is not a legal value for the node.</exception>
/// <returns>Whether the child was found.</returns>
public bool TryGetChild(object value, out IParameterTreeNode child)
{
// Check given value's type.
if (!(value is T))
{
throw new ArgumentException(
$"Tried to get child of {typeof(T)} OR node for a value of type {value.GetType()}");
}
// If correct type, check if value is legal and throw an exception if it isn't.
var typedValue = (T)value;
this.ThrowIfIllegal(typedValue);
// Correct type & legal value --> set child and return.
return(this._children.TryGetValue(typedValue, out child));
}
public void ChildrenAreReturnedCorrectly()
{
// Add several children...
var children = new List <IParameterTreeNode>();
var domainValues = OrNodeTest.Domain.PossibleValues;
for (int i = 0; i < domainValues.Count; i++)
{
IParameterTreeNode child = OrNodeTest.CreateNode(domainValues[i] + "_child");
children.Add(child);
this._decisionNode.AddChild(domainValues[i], child);
}
// ..and compare them with the returned set when querying for the node's children.
Assert.True(
TestUtils.SetsAreEquivalent(children, this._decisionNode.Children),
$"Added children {TestUtils.PrintList(children)}, but return value was {TestUtils.PrintList(this._decisionNode.Children)}");
}
public void ChildrenAreReturnedCorrectly()
{
var andNode = new AndNode();
// Add several children...
var childIdentifiers = new List <string> {
"a", "b", "c", "d"
};
var children = new List <IParameterTreeNode>();
for (int i = 0; i < childIdentifiers.Count; i++)
{
IParameterTreeNode child = AndNodeTest.CreateNode(childIdentifiers[i]);
children.Add(child);
andNode.AddChild(child);
}
// ..and compare them with the returned set when querying for the node's children.
Assert.True(
TestUtils.SetsAreEquivalent(children, andNode.Children),
$"Added children {TestUtils.PrintList(children)}, but return value was {TestUtils.PrintList(andNode.Children)}");
}
/// <summary>
/// Sets the node's child. Overwrites it if it was already set.
/// </summary>
/// <param name="child">The child.</param>
public void SetChild(IParameterTreeNode child)
{
this._child = child;
}
/// <summary>
/// Sets the value for the specified gene on the given child,
/// respecting its parents and the latest parameter origin.
/// </summary>
/// <param name="node">
/// Specifies the gene to set the value for.
/// Is allowed to be an <see cref="AndNode" />. In this case, nothing happens.
/// </param>
/// <param name="parent1">The first parent.</param>
/// <param name="parent2">The second parent.</param>
/// <param name="child">The child. Genome will be modified.</param>
/// <param name="lastParameterOrigin">
/// The latest parameter origin.
/// Influences the probability which parent's gene the child inherits.
/// </param>
/// <returns>
/// The origin of the inherited gene value.
/// For an <see cref="AndNode" />, returns the given parameter origin.
/// </returns>
private ParameterOrigin SetGeneValue(
IParameterTreeNode node,
Genome parent1,
Genome parent2,
Genome child,
ParameterOrigin lastParameterOrigin = ParameterOrigin.Open)
{
// If the node is not a parameter node, we do not have to set a value.
// The parameter origin does not change.
var nodeAsParameter = node as IParameterNode;
if (nodeAsParameter == null)
{
return(lastParameterOrigin);
}
// If it is a parameter node, find the parents' gene values.
var parameterName = nodeAsParameter.Identifier;
var parent1GeneValue = parent1.GetGeneValue(parameterName);
var parent2GeneValue = parent2.GetGeneValue(parameterName);
// If they are equal and the last parameter's origin is open, set child's parameter value to it
// and keep the origin.
if (lastParameterOrigin == ParameterOrigin.Open && object.Equals(parent1GeneValue, parent2GeneValue))
{
child.SetGene(parameterName, parent1GeneValue);
return(lastParameterOrigin);
}
// Otherwise, randomly decide on one of the two parents.
// The probability for the parents is dependent on the last parameter's origin.
double probabilityForFirstParent;
switch (lastParameterOrigin)
{
case ParameterOrigin.FirstParent:
probabilityForFirstParent = 1 - this._crossoverSwitchProbability;
break;
case ParameterOrigin.SecondParent:
probabilityForFirstParent = this._crossoverSwitchProbability;
break;
case ParameterOrigin.Open:
probabilityForFirstParent = 0.5;
break;
default:
throw new ArgumentException($"Parameter origin {lastParameterOrigin} is unknown.");
}
// Throw a (biased) coin and decide on one parent to inherit the gene value from.
var useFirstParent = Randomizer.Instance.Decide(probabilityForFirstParent);
if (useFirstParent)
{
child.SetGene(parameterName, parent1GeneValue);
return(ParameterOrigin.FirstParent);
}
child.SetGene(parameterName, parent2GeneValue);
return(ParameterOrigin.SecondParent);
}
/// <summary>
/// Initializes a new instance of the <see cref="ParameterTree" /> class.
/// </summary>
/// <param name="root">The tree's root.</param>
public ParameterTree(IParameterTreeNode root)
{
this.Root = root;
this.ReplacedParameterFilter = new ReplacedParameterFilter();
}
/// <summary>
/// Adds child for the specified value.
/// </summary>
/// <param name="value">Value from the domain.</param>
/// <param name="child">The child to add.</param>
/// <exception cref="ArgumentException">
/// Thrown if the value is not from the domain or
/// another child was already added for the value.
/// </exception>
public void AddChild(T value, IParameterTreeNode child)
{
this.ThrowIfIllegal(value);
this._children.Add(value, child);
}
/// <summary>
/// Adds a child.
/// </summary>
/// <param name="node">The child to add.</param>
public void AddChild(IParameterTreeNode node)
{
this._children.Add(node);
}
/// <summary>
/// Returns whether the given <see cref="IParameterTreeNode"/> represents the parameter described by the given
/// identifier.
/// </summary>
/// <param name="node">The node to check.</param>
/// <param name="identifier">The identifier to check for.</param>
/// <returns>True if and only if the node is an <see cref="IParameterNode"/> with identifier equal to the given
/// one.
/// </returns>
public static bool RepresentsParameter(IParameterTreeNode node, string identifier)
{
return(node is IParameterNode parameterNode && parameterNode.Identifier == identifier);
}