public void split() {
if (m_ilist == null) throw new IllegalStateException("Frozen. Cannot split.");
int numLeftChildren = 0;
boolean[] toLeftChild = new boolean[m_instIndices.length];
for (int i = 0; i < m_instIndices.length; i++) {
Instance instance = m_ilist.get(m_instIndices[i]);
FeatureVector fv = (FeatureVector) instance.getData();
if (fv.value(m_gainRatio.getMaxValuedIndex()) <= m_gainRatio.getMaxValuedThreshold()) {
toLeftChild[i] = true;
numLeftChildren++;
} else toLeftChild[i] = false;
}
logger.info(
"leftChild.size="
+ numLeftChildren
+ " rightChild.size="
+ (m_instIndices.length - numLeftChildren));
int[] leftIndices = new int[numLeftChildren];
int[] rightIndices = new int[m_instIndices.length - numLeftChildren];
int li = 0, ri = 0;
for (int i = 0; i < m_instIndices.length; i++) {
if (toLeftChild[i]) leftIndices[li++] = m_instIndices[i];
else rightIndices[ri++] = m_instIndices[i];
}
m_leftChild = new Node(m_ilist, this, m_minNumInsts, leftIndices);
m_rightChild = new Node(m_ilist, this, m_minNumInsts, rightIndices);
}
protected List<Double> serializeFv(FeatureVector fv) {
List<Double> features = new ArrayList<>();
int numLocations = fv.numLocations();
int[] indices = fv.getIndices();
for (int index = 0; index < numLocations; index++) {
int featureIndex = indices[index];
double value = fv.value(featureIndex);
features.add(value);
}
return features;
}
private Node getLeaf(Node node, FeatureVector fv) {
if (node.getLeftChild() == null && node.getRightChild() == null) return node;
else if (fv.value(node.getGainRatio().getMaxValuedIndex())
<= node.getGainRatio().getMaxValuedThreshold()) return getLeaf(node.getLeftChild(), fv);
else return getLeaf(node.getRightChild(), fv);
}