org.grouplens.lenskit.transform.normalize

Class DefaultUserVectorNormalizer

java.lang.Object

org.grouplens.lenskit.transform.normalize.DefaultUserVectorNormalizer

All Implemented Interfaces:

Serializable, UserVectorNormalizer

@Shareable
public class DefaultUserVectorNormalizer
extends Object
implements UserVectorNormalizer, Serializable

Default user vector normalizer that delegates to a generic VectorNormalizer.

Since:

0.11

Author:

GroupLens Research

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected VectorNormalizer	delegate

Constructor Summary

Constructors

Constructor and Description
DefaultUserVectorNormalizer() Construct a new user vector normalizer that uses the identity normalization.
DefaultUserVectorNormalizer(VectorNormalizer norm) Construct a new user vector normalizer wrapping a generic vector normalizer.

Method Summary

Methods

Modifier and Type	Method and Description
VectorNormalizer	getVectorNormalizer() Get the delegate vector normalizer.
VectorTransformation	makeTransformation(long user, SparseVector vector) Make a vector transformation for a user.
MutableSparseVector	normalize(long user, SparseVector vector, MutableSparseVector target) Normalize a vector with respect to a user vector.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

delegate

protected final VectorNormalizer delegate

Constructor Detail

DefaultUserVectorNormalizer

public DefaultUserVectorNormalizer()

Construct a new user vector normalizer that uses the identity normalization.

DefaultUserVectorNormalizer

@Inject
public DefaultUserVectorNormalizer(VectorNormalizer norm)

Construct a new user vector normalizer wrapping a generic vector normalizer.

Parameters:

norm - The generic normalizer to use.

Method Detail

getVectorNormalizer

public VectorNormalizer getVectorNormalizer()

Get the delegate vector normalizer.

Returns:

The vector normalizer used by this UVN.

normalize

public MutableSparseVector normalize(long user,
                            @Nonnull
                            SparseVector vector,
                            @Nullable
                            MutableSparseVector target)

Description copied from interface: UserVectorNormalizer

Normalize a vector with respect to a user vector.

Specified by:

normalize in interface UserVectorNormalizer

Parameters:

user - The user to normalize a vector for.

vector - The user's vector for reference.

target - The vector to normalize. If null, the user vector is normalized.

Returns:

The target vector, if specified. Otherwise, a fresh mutable vector containing a normalized copy of the user vector is returned.

makeTransformation

public VectorTransformation makeTransformation(long user,
                                      SparseVector vector)

Description copied from interface: UserVectorNormalizer

Make a vector transformation for a user. The resulting transformation will be applied to user vectors to normalize and denormalize them.

Specified by:

makeTransformation in interface UserVectorNormalizer

Parameters:

user - The user ID to normalize for.

vector - The user's vector to use as the reference vector.

Returns:

The vector transformaition normalizing for this user.