@Override
protected InformationLossWithBound<InformationLossDefault> getInformationLossInternal(
final Node node, final HashGroupify g) {
if (node.getLowerBound() != null) {
return new InformationLossWithBound<InformationLossDefault>(
(InformationLossDefault) node.getLowerBound(),
(InformationLossDefault) node.getLowerBound());
}
// Init
double result = 0;
// For each column
for (int column = 0; column < hierarchies.length; column++) {
// Check for cached value
final int state = node.getTransformation()[column];
double value = cache[column][state];
if (value == NA) {
value = 0d;
final int[][] cardinality = cardinalities[column];
final int[][] hierarchy = hierarchies[column];
for (int in = 0; in < hierarchy.length; in++) {
final int out = hierarchy[in][state];
final double a = cardinality[in][0];
final double b = cardinality[out][state];
if (a != 0d) {
value += a * log2(a / b);
}
}
cache[column][state] = value;
}
result += value;
}
result = round(result == 0.0d ? result : -result);
return new InformationLossDefaultWithBound(result, result);
}
