/**
* Construct a new vector from a key set and value array.
*
* @param ks The key set. Used as-is, and will be modified. Pass a clone, usually.
* @param vs The value array.
*/
@SuppressWarnings("PMD.ArrayIsStoredDirectly")
SparseVector(LongKeyDomain ks, double[] vs) {
assert vs.length >= ks.domainSize();
keys = ks;
keys.acquire();
values = vs;
}
/**
* Construct a new vector from the contents of a map. The key domain is the key set of the map.
* Therefore, no new keys can be added to this vector.
*
* @param keyValueMap A map providing the values for the vector.
*/
SparseVector(Long2DoubleMap keyValueMap) {
keys = LongKeyDomain.fromCollection(keyValueMap.keySet(), true);
final int len = keys.domainSize();
values = new double[len];
for (int i = 0; i < len; i++) {
values[i] = keyValueMap.get(keys.getKey(i));
}
}
/**
* Fast iterator over entries (it can reuse entry objects).
*
* @param state The state of entries to iterate.
* @return a fast iterator over all key/value pairs
* @see it.unimi.dsi.fastutil.longs.Long2DoubleMap.FastEntrySet#fastIterator()
* Long2DoubleMap.FastEntrySet.fastIterator()
* @since 0.11
*/
public Iterator<VectorEntry> fastIterator(VectorEntry.State state) {
IntIterator iter;
switch (state) {
case SET:
iter = keys.activeIndexIterator(isMutable());
break;
case UNSET:
{
iter = keys.clone().invert().activeIndexIterator(false);
break;
}
case EITHER:
{
iter = IntIterators.fromTo(0, keys.domainSize());
break;
}
default: // should be impossible
throw new IllegalArgumentException("invalid entry state");
}
return new FastIterImpl(iter, state);
}
/**
* Construct a new sparse vector with a particular domain. Allocates the value storage.
*
* @param ks The key set. Used as-is, and will be modified. Pass a clone, usually.
*/
SparseVector(LongKeyDomain ks) {
this(ks, new double[ks.domainSize()]);
ks.setAllActive(false);
}