/**
* 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);
}
/**
* Creates a new square matrix whose number of rows and columns match the dimensionality of the
* given vector. It also places the values of the vector on the diagonal of the matrix.
*
* @param diagonal The vector of diagonal values.
* @return A new, square matrix with the diagonal elements equal to the elements of the given
* vector.
*/
public MatrixType createDiagonal(final Vectorizable diagonal) {
final Vector vector = diagonal.convertToVector();
final int dimensionality = vector.getDimensionality();
// Create the matrix.
final MatrixType result = this.createMatrix(dimensionality, dimensionality);
// Set the diagonal values.
for (VectorEntry entry : vector) {
final int i = entry.getIndex();
result.setElement(i, i, entry.getValue());
}
return result;
}
/**
* 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");
}
}
