private List <Tree> Split()
{
var splitInfo = FindBestSplit();
//var splitInfo = FindBestRandomSplit();
int bestLocalDimIndex = splitInfo.Item1;
double bestSplit = splitInfo.Item2;
double maxExpectedInfo = splitInfo.Item3;
if (bestLocalDimIndex == -1)
{
return(null);
}
int bestGlobalDimIndex = this.TargetFeatures[bestLocalDimIndex];
bool[] filter = TrainPoints.FeatureCols[bestGlobalDimIndex].Geq(bestSplit);
var upperMinCorner = new double[NDim];
MinCorner.CopyTo(upperMinCorner, 0);
upperMinCorner[bestLocalDimIndex] = bestSplit;
var lowerMaxCorner = new double[NDim];
MaxCorner.CopyTo(lowerMaxCorner, 0);
lowerMaxCorner[bestLocalDimIndex] = bestSplit;
var upperTree = new Tree(
TrainPoints.Filter(filter),
this.TargetFeatures,
upperMinCorner,
MaxCorner,
includeMax: IncludeMax,
normalizingConstant: NormalizingConstant
);
bool[] lowerIncludeMax = new bool[NDim];
IncludeMax.CopyTo(lowerIncludeMax, 0);
lowerIncludeMax[bestLocalDimIndex] = false;
Yarr.InlineNot(filter);
var lowerTree = new Tree(
TrainPoints.Filter(filter),
this.TargetFeatures,
MinCorner,
lowerMaxCorner,
includeMax: lowerIncludeMax,
normalizingConstant: NormalizingConstant
);
this.SplitDim = bestLocalDimIndex;
this.SplitVal = bestSplit;
return(new List <Tree> {
upperTree, lowerTree
});
}
private Tree MakeTree()
{
var cols = RandomUtils.Choice(this.ColIndices, this.ColsPerTree).ToArray();
bool[] filter = Yarr.InlineNot(this.Data.HasNaN(cols));
var filteredData = this.Data.Filter(filter);
var result = new Tree(
filteredData,
cols,
Yarr.FancyIndex(this.GlobalMinCorner, cols),
Yarr.FancyIndex(this.GlobalMaxCorner, cols)
);
result.Train();
return(result);
}
public Score Score(RecordSet data, bool parallel = true)
{
//NOTE: ignore parallel parameter
double[] sScores = Yarr.Repeat(double.NaN, data.NRows);
double[] bScores = Yarr.Repeat(double.NaN, data.NRows);
bool[] filter = Yarr.InlineNot(data.HasNaN(this.TargetFeatures));
var filteredData = data.Filter(filter);
data = null; // unlikely to let anything be GC'ed (lots of references to same obj) but it can't hurt
this._Score(
filteredData,
Yarr.Range(filteredData.NRows).MakeSlice(),
sScores,
bScores
);
return(new Score(sScores, bScores));
}