/**
* Adds a new distance functor for the given attribute data type.
*
* @param type the attribute data type
* @param d the distance functor to use on the data type
*/
public static final void putDistanceFunctorFor(String type, Distance d) {
Map<String, Distance> fs = distanceMap.get(type);
if (fs == null) {
fs = new HashMap<String, Distance>();
}
fs.put(d.toString(), d);
distanceMap.put(type, fs);
}