Exemple #1
0
func splitExamples(t *pb.TreeNode, e Examples) (left Examples, right Examples) {
	by(func(e1, e2 *pb.Example) bool {
		return e1.Features[t.GetFeature()] < e2.Features[t.GetFeature()]
	}).Sort(e)
	splitIndex := 0
	for i, ex := range e {
		splitIndex = i
		if ex.Features[t.GetFeature()] > t.GetSplitValue() {
			break
		}
	}
	left, right = e[:splitIndex], e[splitIndex:]
	return
}
Exemple #2
0
func flattenTree(f *fastTreeEvaluator, current *pb.TreeNode, currentIndex int) {
	glog.Infof("Flattening tree at index %v", currentIndex)
	if isLeaf(current) {
		f.nodes[currentIndex] = flatNode{
			value:   current.GetLeafValue(),
			feature: leafFeatureID,
		}
		return
	}

	// append child nodes
	// since we push on N + 2 elements, we want index N + 1, hence len(f.nodes)
	leftChild := len(f.nodes)
	f.nodes = append(f.nodes, flatNode{}, flatNode{})

	f.nodes[currentIndex] = flatNode{
		value:     current.GetSplitValue(),
		feature:   current.GetFeature(),
		leftChild: leftChild,
	}

	flattenTree(f, current.GetLeft(), leftChild)
	flattenTree(f, current.GetRight(), leftChild+1)
}
Exemple #3
0
func printNode(node *pb.TreeNode, c *codeWriter) {
	if node.GetLeft() == nil && node.GetRight() == nil {
		c.WriteString(fmt.Sprintf("return %v;\n", node.GetLeafValue()))
		return
	}

	c.WriteString(fmt.Sprintf("if (%v(f[%v] < %v)) {\n", getAnnotation(node), node.GetFeature(), node.GetSplitValue()))
	{
		c.indentLevel++
		printNode(node.GetLeft(), c)
		c.indentLevel--
	}
	c.WriteString("} else {\n")
	{
		c.indentLevel++
		printNode(node.GetRight(), c)
		c.indentLevel--
	}
	c.WriteString("}\n")
}