/** Computes the difference between two given attribute values. */
protected double difference(int index, double val1, double val2) {
switch (m_instances.attribute(index).type()) {
case Attribute.NOMINAL:
// If attribute is nominal
if (Instance.isMissingValue(val1)
|| Instance.isMissingValue(val2)
|| ((int) val1 != (int) val2)) {
return 1;
} else {
return 0;
}
case Attribute.NUMERIC:
// If attribute is numeric
if (Instance.isMissingValue(val1) || Instance.isMissingValue(val2)) {
if (Instance.isMissingValue(val1) && Instance.isMissingValue(val2)) {
return 1;
} else {
double diff;
if (Instance.isMissingValue(val2)) {
diff = norm(val1, index);
} else {
diff = norm(val2, index);
}
if (diff < 0.5) {
diff = 1.0 - diff;
}
return diff;
}
} else {
return norm(val1, index) - norm(val2, index);
}
default:
return 0;
}
}
