/**
* 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));
}
}
/**
* Check whether an entry is set.
*
* @param entry The entry.
* @return {@code true} if the entry is set in this vector.
* @throws IllegalArgumentException if the entry is not from this vector or another vector sharing
* the same key domain. Only vectors and their side channels share key domains for the
* purposes of this check.
*/
public boolean isSet(VectorEntry entry) {
final SparseVector evec = entry.getVector();
final int eind = entry.getIndex();
if (evec == null) {
throw new IllegalArgumentException("entry is not associated with a vector");
} else if (!keys.isCompatibleWith(evec.keys)) {
throw new IllegalArgumentException("entry does not have safe key domain");
}
assert entry.getKey() == keys.getKey(eind);
return keys.indexIsActive(eind);
}
/**
* Get the value for the entry's key.
*
* @param entry A {@code VectorEntry} with the key to look up
* @return the key's value
* @throws IllegalArgumentException if the entry is unset, or if it is not from this vector or
* another vector sharing the same key domain. Only vectors and their side channels share key
* domains for the purposes of this check.
*/
public double get(VectorEntry entry) {
final SparseVector evec = entry.getVector();
final int eind = entry.getIndex();
if (evec == null) {
throw new IllegalArgumentException("entry is not associated with a vector");
} else if (!evec.keys.isCompatibleWith(keys)) {
throw new IllegalArgumentException("entry does not have safe key domain");
}
assert entry.getKey() == keys.getKey(eind);
if (keys.indexIsActive(eind)) {
return values[eind];
} else {
throw new IllegalArgumentException("Key " + entry.getKey() + " is not set");
}
}
/**
* Get the value for {@var key}.
*
* @param key the key to look up
* @param dft The value to return if the key is not in the vector
* @return the value (or {@var dft} if the key is not set to a value)
*/
public double get(long key, double dft) {
final int idx = keys.getIndexIfActive(key);
if (idx >= 0) {
return values[idx];
} else {
return dft;
}
}
/**
* Get the value for {@var key}.
*
* @param key the key to look up; the key must be in the key set.
* @return the key's value
* @throws IllegalArgumentException if {@var key} is not in the key set.
*/
public double get(long key) {
final int idx = keys.getIndexIfActive(key);
if (idx >= 0) {
return values[idx];
} else {
throw new IllegalArgumentException("Key " + key + " is not in the key set");
}
}
/**
* Get the collection of values of this vector.
*
* @return The collection of all values in this vector.
*/
public DoubleCollection values() {
DoubleArrayList lst = new DoubleArrayList(size());
IntIterator iter = keys.activeIndexIterator(false);
while (iter.hasNext()) {
int idx = iter.nextInt();
lst.add(values[idx]);
}
return lst;
}
/**
* 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);
}
/**
* Get the size of this vector (the number of keys).
*
* @return The number of keys in the vector. This is at most the size of the key domain.
*/
public int size() {
return keys.size();
}
/**
* Get the set of unset keys. This is \(D \\ S\), where \(D\) is the key domain and \(S\) the key
* set.
*/
public LongSortedSet unsetKeySet() {
return keys.clone().invert().activeSetView();
}
/**
* Get the set of keys of this vector. It is a subset of the key domain. The keys will be in
* sorted order.
*
* @return The set of keys used in this vector.
*/
public LongSortedSet keySet() {
return keys.activeSetView();
}
/**
* Get the key domain for this vector. All keys used are in this set. The keys will be in sorted
* order.
*
* @return The key domain for this vector.
*/
public LongSortedSet keyDomain() {
return keys.domain();
}
/**
* Query whether the vector contains an entry for the key in question.
*
* @param key The key to search for.
* @return {@code true} if the key exists.
*/
public boolean containsKey(long key) {
return keys.keyIsActive(key);
}
