/// <summary>
/// Parse an ADF branch
/// </summary>
/// <param name="adfNode"></param>
/// <param name="WhichADF"></param>
/// <param name="Program"></param>
/// <returns></returns>
private GPProgramBranchADF LoadBranchADF(XmlNode adfNode, short WhichADF, GPProgram Program)
{
//
// First step, parse out the number of arguments
XmlNode xmlNode = adfNode.SelectSingleNode("ParameterCount");
byte ParameterCount = Convert.ToByte(xmlNode.InnerText);
//
// Create the Branch tree
GPProgramBranchADF adf = new GPProgramBranchADF(Program, 0, WhichADF, ParameterCount);
//
// Get the root ADF node
xmlNode = adfNode.SelectSingleNode("GPNode");
adf.Root = ReadGPNode(xmlNode);
adf.UpdateStats();
return(adf);
}
/// <summary>
/// This method performs crossover on the ADF branch.
/// 90% of the time internal nodes are selected and 10% of the time
/// leaf nodes are selected.
/// TODO: Parameterize those percentages
///
/// If either one of the selected nodes is a function that accepts only
/// terminals as parameters, no crossover is performed.
///
/// </summary>
/// <param name="sibling"></param>
public override void Crossover(GPProgramBranch sibling)
{
GPProgramBranchADF rightADF = (GPProgramBranchADF)sibling;
//
// Step 1: Find a node in the left tree
double TypeLeft = GPUtilities.rngNextDouble();
GPProgramBranchFactory.FindResult findLeft = null;
bool DoneLeft = false;
while (!DoneLeft)
{
int NodeLeft = GPUtilities.rngNextInt(m_Branch.CountNodes);
findLeft = FindNode(null, m_Branch.Root, NodeLeft);
if (TypeLeft < 0.90 && (findLeft.Node is GPNodeFunction))
{
DoneLeft = true;
}
else if (TypeLeft >= 0.90 && (findLeft.Node is GPNodeTerminal))
{
DoneLeft = true;
}
else if (m_Branch.CountNodes == 1)
{
DoneLeft = true;
}
}
//
// If the node is a function that only accepts terminal inputs, then crossover is not allowed
if (findLeft.Node is GPNodeFunction && ((GPNodeFunction)findLeft.Node).TerminalParameters)
{
return;
}
if (findLeft.Parent != null && findLeft.Parent is GPNodeFunction && ((GPNodeFunction)findLeft.Parent).TerminalParameters)
{
return;
}
//
// Step 2: Find a node in the right tree
double TypeRight = GPUtilities.rngNextDouble();
GPProgramBranchFactory.FindResult findRight = null;
bool DoneRight = false;
while (!DoneRight)
{
int NodeRight = GPUtilities.rngNextInt(rightADF.CountNodes);
findRight = FindNode(null, rightADF.Root, NodeRight);
if (TypeRight < 0.90 && (findRight.Node is GPNodeFunction))
{
DoneRight = true;
}
else if (TypeRight >= 0.90 && (findRight.Node is GPNodeTerminal))
{
DoneRight = true;
}
else if (rightADF.CountNodes == 1)
{
DoneRight = true;
}
}
//
// If the node is a function that only accepts terminal inputs, then crossover is not allowed
if (findRight.Node is GPNodeFunction && ((GPNodeFunction)findRight.Node).TerminalParameters)
{
return;
}
if (findRight.Parent != null && findRight.Parent is GPNodeFunction && ((GPNodeFunction)findRight.Parent).TerminalParameters)
{
return;
}
//
// Step 3: Swap the references
if (findLeft.Parent == null)
{
m_Branch.Root = findRight.Node;
}
else
{
findLeft.Parent.Children[findLeft.ChildNumber] = findRight.Node;
}
if (findRight.Parent == null)
{
rightADF.Root = findLeft.Node;
}
else
{
findRight.Parent.Children[findRight.ChildNumber] = findLeft.Node;
}
//
// Update the stats for these trees
m_Branch.UpdateStats();
rightADF.UpdateStats();
}
