/**
* 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);
}
/**
* Tests to see if the specified metric name is known for the given attribute data type.
*
* @param type the attribute type
* @param s the name of the distance metric to look for
* @return true if <code>s</code> is the name of a known metric for the type
* @throws UnknownDistanceException if the type is unknown. XXX: shouldn't this be the other way
* around?
*/
public static final boolean isDistanceFor(String type, String s) throws UnknownDistanceException {
check(type);
Map<String, Distance> values = distanceMap.get(type);
if (values != null) {
return values.containsKey(s.toLowerCase());
} else {
throw new UnknownDistanceException("Attribute type not found: " + type);
}
}
/**
* Tests to see if the specified metric name is known for the given attribute data type.
*
* @param type the attribute type
* @param s the name of the distance metric to look for
* @return true if <code>s</code> is the name of a known metric for the type
* @throws UnknownDistanceException if the type is unknown. XXX: shouldn't this be the other way
* around?
*/
public static final boolean isDistanceFor(Measurable type, String s)
throws UnknownDistanceException {
Map<String, Distance> values = distanceMap.get(type.getType());
if (values != null) {
return values.containsKey(s.toLowerCase());
} else {
throw new UnknownDistanceException(type, s);
}
}
/**
* Copies all the distance functors from <code>from</code> attribute type to <code>to</code>
* attribute type.
*
* @param to the attribute type to get the copies
* @param from the attribute type to receive the distance functor references
*/
public static final void useSameDistances(String to, String from) {
check(from);
Map<String, Distance> fromValues = distanceMap.get(from);
Map<String, Distance> toValues = distanceMap.get(to);
if (fromValues != null) {
if (toValues != null) {
toValues.putAll(fromValues);
} else {
toValues = new HashMap<String, Distance>();
toValues.putAll(fromValues);
distanceMap.put(to, toValues);
}
}
}
/**
* Gets the distance functor for the given type.
*
* @param type the attribute data type
* @param metric the metric name
* @return the metric
* @throws UnknownDistanceException if the metric isn't found
*/
public static final Distance getDistanceFunctor(String type, String metric)
throws UnknownDistanceException {
check(type);
metric = metric.toLowerCase();
if (!distanceMap.containsKey(type)) {
throw new UnknownDistanceException("Attribute type not found: " + type);
} else {
Map<String, Distance> distances = distanceMap.get(type);
if (!distances.containsKey(metric)) {
throw new UnknownDistanceException(type, metric);
} else {
return (Distance) distances.get(metric);
}
}
}