private static IDecisionNode NodeToDecisionTree(IDataNode node)
{
if (node is DataLeaf)
{
DataLeaf leaf = (DataLeaf)node;
Tactic tactic = EnumUtils.GetEnumValues <Tactic>().MaxBy(t => leaf.ClassDistribution[(int)t]);
return(new DecisionLeaf(tactic));
}
else if (node is AttributeSplit)
{
AttributeSplit attributeSplit = (AttributeSplit)node;
return(new DecisionNode {
Partitioner = new ContinuousPartitioner((ContinuousAxis)attributeSplit.Axis, attributeSplit.SplitValue),
Left = NodeToDecisionTree(attributeSplit.Left),
Right = NodeToDecisionTree(attributeSplit.Right),
});
}
else if (node is CategoricalSplit)
{
CategoricalSplit categoricalSplit = (CategoricalSplit)node;
return(new DecisionNode {
Partitioner = new CategoricalPartitioner(
(CategoricalAxis)categoricalSplit.Axis,
PolicyHelper.BitsToCategories((CategoricalAxis)categoricalSplit.Axis, categoricalSplit.Categories).ToArray()),
Left = NodeToDecisionTree(categoricalSplit.Left),
Right = NodeToDecisionTree(categoricalSplit.Right),
});
}
else
{
throw new ArgumentException("Unknown node type: " + node);
}
}
private static List <DataPoint> EpisodesToDataPoints(List <Episode> episodes)
{
return(episodes.AsParallel().Select(episode => new DataPoint {
Episode = episode,
Class = (byte)episode.Tactic,
Weight = (float)episode.Weight,
Attributes =
EnumUtils.GetEnumValues <ContinuousAxis>()
.Select(axis => (float)ContinuousAxisEvaluator.Evaluate(axis, episode.World, episode.Hero))
.ToArray(),
Categories =
EnumUtils.GetEnumValues <CategoricalAxis>()
.Select(axis => PolicyHelper.CategoriesToBits(CategoricalAxisEvaluator.Evaluate(axis, episode.World, episode.Hero)))
.ToArray(),
}).ToList());
}