public static GeneratedDataColumn CreateNewRandom(GeneticAlgorithmManager ga_mgr)
{
//do some work to create the new column
var column = new GeneratedDataColumn();
column._scaling = ga_mgr.rando.NextDouble() * 20 - 10.0;
//this allows probs to change after each generation if desired
var operations = new List <Tuple <GeneratedDataColumn.FormulaOptions, double> >();
operations.Add(Tuple.Create(GeneratedDataColumn.FormulaOptions.INV, 10.0));
operations.Add(Tuple.Create(GeneratedDataColumn.FormulaOptions.LN, 10.0));
operations.Add(Tuple.Create(GeneratedDataColumn.FormulaOptions.SQR, 10.0));
operations.Add(Tuple.Create(GeneratedDataColumn.FormulaOptions.SQRT, 10.0));
operations.Add(Tuple.Create(GeneratedDataColumn.FormulaOptions.TANH, 10.0));
operations.Add(Tuple.Create(GeneratedDataColumn.FormulaOptions.NONE, 10.0));
var operation_picker = WeightedSelector.Create(operations);
column._formula = operation_picker.PickRandom(ga_mgr.rando);
//forces to be a double data column here
DataColumn baseColumn = null;
do
{
int index = ga_mgr.rando.Next(ga_mgr.dataPointMgr._columns.Count);
baseColumn = ga_mgr.dataPointMgr._columns[index];
}while (baseColumn._type != DataValueTypes.NUMBER);
column._baseColumn = baseColumn as DoubleDataColumn;
column._type = DataValueTypes.NUMBER;
column.CreateValues(ga_mgr.dataPointMgr);
return(column);
}
public static IEnumerable <Tree> SwapNodesBetweenTrees(GeneticAlgorithmManager ga_mgr, List <Tree> treesInPopulation)
{
Random rando = ga_mgr.rando;
//node swap
Tree tree1 = treesInPopulation[rando.Next(treesInPopulation.Count())];
Tree tree2 = treesInPopulation[rando.Next(treesInPopulation.Count())];
if (tree1._root.IsTerminal || tree2._root.IsTerminal)
{
//terminal node for a root means no useful swapping to be done
yield break;
}
tree1.SetStructuralLocationsForNodes();
tree2.SetStructuralLocationsForNodes();
Tree tree1_copy = tree1.Copy();
Tree tree2_copy = tree2.Copy();
tree1_copy._source = "swap";
tree2_copy._source = "swap";
//tries to pick good nodes to swap around
//TODO look into a better way to pick nodes
//TODO make it easier to select a node with equal weight
var tree1_node_picker = new WeightedSelector <YesNoMissingTreeNode>(
tree1.GetNodesOfType <YesNoMissingTreeNode>().Select(c => Tuple.Create(c, 1.0)));
var tree2_node_picker = new WeightedSelector <YesNoMissingTreeNode>(
tree2.GetNodesOfType <YesNoMissingTreeNode>().Select(c => Tuple.Create(c, 1.0)));
var node1_picked = tree1_node_picker.PickRandom(ga_mgr.rando);
var node2_picked = tree2_node_picker.PickRandom(ga_mgr.rando);
if (node1_picked == null || node2_picked == null)
{
//trap exists for those trees where there are no classification nodes
yield break;
}
TreeNode node1 = tree1_copy.GetNodeAtStructualLocation(node1_picked._structuralLocation);
TreeNode node2 = tree2_copy.GetNodeAtStructualLocation(node2_picked._structuralLocation);
TreeNode.SwapNodesInTrees(node1, node2);
//stick both trees into the next gen
if (tree1_copy._nodes.Count > 0)
{
yield return(tree1_copy);
}
if (tree2_copy._nodes.Count > 0)
{
yield return(tree2_copy);
}
}
public static IEnumerable <Tree> OptimizeSplitForNode(GeneticAlgorithmManager ga_mgr, List <Tree> treesInPopulation)
{
//pick a random tree
Random rando = ga_mgr.rando;
Tree tree1 = treesInPopulation[rando.Next(treesInPopulation.Count())];
Tree tree1_copy = tree1.Copy();
var nodes_to_choose_from = tree1_copy.GetNodesOfType <YesNoMissingTreeNode>().Where(c => c.Test is LessThanEqualTreeTest);
if (!nodes_to_choose_from.Any())
{
//empty collection test
yield break;
}
var node_picker = new WeightedSelector <YesNoMissingTreeNode>(
nodes_to_choose_from.Select(c => Tuple.Create(c, 1.0))
);
YesNoMissingTreeNode node1_copy = node_picker.PickRandom(rando);
if (node1_copy == null)
{
yield break;
}
//iterate through all values for the node and use the one with the best impurity
if (OptimizeTest(node1_copy, ga_mgr))
{
tree1_copy._source = "optimize value";
yield return(tree1_copy);
}
yield break;
}
public static IEnumerable <Tree> SplitNodeAndOptimizeTests(GeneticAlgorithmManager ga_mgr, List <Tree> treesInPopulation)
{
//find a grab a tree
Tree tree1 = treesInPopulation[ga_mgr.rando.Next(treesInPopulation.Count())];
//uses the traversal count for selecting
var node_picker = new WeightedSelector <ClassificationTreeNode>(
tree1.GetNodesOfType <ClassificationTreeNode>().Select(c => Tuple.Create(c, (double)c._traverseCount))
);
ClassificationTreeNode node1 = node_picker.PickRandom(ga_mgr.rando);
tree1.SetStructuralLocationsForNodes();
if (node1.matrix == null)
{
}
var matrix_rows = node1.matrix.GetRowsOrderedByCount().ToList();
//trap is here in case there are fewer than 2 "top" rows to split on
if (matrix_rows.Count >= 2)
{
//TODO improve this structural business to be cleaner and more obvious if it belongs to the Node or Tree
Tree tree1_copy = tree1.Copy();
TreeNode node1_copy = tree1_copy.GetNodeAtStructualLocation(node1._structuralLocation);
//grab the node with the greatest traverse count (that is terminal)
//determine the two most popular classes from there (rows in the confusion table)
//create a random test for the current node (change from classification to decision)
//TODO create a proper factory for this code
var node1_decision = new YesNoMissingTreeNode();
node1_decision.CreateRandom(ga_mgr);
node1_decision._parent = node1_copy._parent;
var item1 = node1.Classification;
var item2 = 0;
var item3 = 0;
//create the two classification nodes
var node1a_class = new ClassificationTreeNode();
node1a_class.Classification = item1;
node1a_class._parent = node1_decision;
var node1b_class = new ClassificationTreeNode();
node1b_class.Classification = item2;
node1b_class._parent = node1_decision;
var node1c_class = new ClassificationTreeNode();
node1c_class.Classification = item3;
node1c_class._parent = node1_decision;
node1_decision._trueNode = node1a_class;
node1_decision._falseNode = node1b_class;
node1_decision._missingNode = node1c_class;
//add the two nodes with the most popular classes
//TODO create a "replace node" operation to standardize this code
tree1_copy.RemoveNodeWithChildren(node1_copy);
node1_copy.UpdateParentReference(node1_decision);
tree1_copy.AddNodeWithChildren(node1_decision);
//return the new tree with that change
//try to optimize the node
bool opTest = OptimizeTest(node1_decision, ga_mgr);
tree1_copy._source = "node split";
if (opTest)
{
tree1_copy._source += " w/ op";
}
yield return(tree1_copy);
}
}
public List <Tree> ProcessTheNextGeneration(List <Tree> treesInPopulation)
{
//do an initial scoring
treesInPopulation = ScoreTreesAndReturnKept(treesInPopulation, 0);
for (int generationNumber = 0; generationNumber < _gaOptions.generations; generationNumber++)
{
var newTreesThisGen = new List <Tree>();
Logger.WriteLine("generation: " + generationNumber);
//this allows probs to change after each generation if desired
var operations = new List <Tuple <GeneticOperations.GeneticOperation, double> >();
operations.Add(Tuple.Create((GeneticOperations.GeneticOperation)GeneticOperations.SwapNodesBetweenTrees, _gaOptions.Prob_ops_swap));
operations.Add(Tuple.Create((GeneticOperations.GeneticOperation)GeneticOperations.SplitNodeAndOptimizeTests, _gaOptions.prob_node_split));
operations.Add(Tuple.Create((GeneticOperations.GeneticOperation)GeneticOperations.CreateRandomTree, _gaOptions.Prob_ops_new_tree));
operations.Add(Tuple.Create((GeneticOperations.GeneticOperation)GeneticOperations.OptimizeSplitForNode, 10.0));
//operations.Add(Tuple.Create((GeneticOperations.GeneticOperation)GeneticOperations.OptimizeClassesForTree, 10.0));
operations.Add(Tuple.Create((GeneticOperations.GeneticOperation)GeneticOperations.DeleteNodeFromTree, _gaOptions.prob_ops_delete));
//operations.Add(Tuple.Create((GeneticOperations.GeneticOperation)GeneticOperations.SuperSplit, 5.0));
var operation_picker = new WeightedSelector <GeneticOperations.GeneticOperation>(operations);
Parallel.For(0, _gaOptions.PopulationSize, index =>
{
var operation = operation_picker.PickRandom(rando);
var newTrees = operation(this, treesInPopulation).ToList();
//TODO determine if this is needed
lock (newTreesThisGen)
{
newTreesThisGen.AddRange(newTrees);
}
});
treesInPopulation.AddRange(newTreesThisGen);
treesInPopulation = ScoreTreesAndReturnKept(treesInPopulation, generationNumber);
foreach (var element in treesInPopulation.GroupBy(c => c._source))
{
Logger.WriteLine(string.Format("{0} has {1} = {2:0.000}",
element.Key, element.Count(),
1.0 * element.Count() / treesInPopulation.Count));
}
//thin down the herd and take pop size or total
treesInPopulation = treesInPopulation.Distinct()
.OrderByDescending(c => c._prevResults.MetricResult)
.Take((int)(_gaOptions.populationSize * _gaOptions.prob_population_to_keep))
.ToList();
//output some info on best
//Logger.WriteLine(string.Join("\r\n", starter.Take(10).Select(c => c._prevResults.ToString())));
Logger.WriteLine("");
foreach (var tree in treesInPopulation.Take(10))
{
Logger.WriteLine("{0:0.0000} ({2:0.0000}, {3}, {1})",
tree._prevResults.MetricResult,
tree._source, tree._prevResults.AverageLoss,
tree._prevResults.tree_nodeCount);
}
foreach (var tree in treesInPopulation.Take(1))
{
Logger.WriteLine("");
Logger.WriteLine(tree);
Logger.WriteLine(tree._prevResults);
}
OnProgressUpdated(100 * generationNumber / Math.Max(_gaOptions.generations, 1));
}
OnProgressUpdated(100);
return(treesInPopulation);
}
