com.cloudera.oryx.app.als

Interface FeatureVectors

All Known Implementing Classes:

FeatureVectorsPartition, PartitionedFeatureVectors

public interface FeatureVectors

Encapsulates a feature vectors, keyed by an ID, and associated data structures. This supports the representation of user-feature and item-feature vectors in ALSServingModel or ALSSpeedModel.

Method Summary

Modifier and Type	Method and Description
void	addAllIDsTo(Collection<String> allIDs) Adds all IDs that are mapped to a feature vector to a given collection
void	addAllRecentTo(Collection<String> allRecent) Add all recently set IDs to the given collection
float[]	getVector(String id)
double[]	getVTV(boolean background)
void	removeAllIDsFrom(Collection<String> allIDs) Removes all IDs that are mapped to a feature vector from a given collection
void	retainRecentAndIDs(Collection<String> newModelIDs) Given IDs that are part of a new model, and whose values are going to be sent later, retain only IDs that are also in the new model (or have been recently seen -- possibly since last model was built), and remove the rest.
void	setVector(String id, float[] vector) Sets the value of a feature vector for an ID.
int	size()

Method Detail

size

int size()

Returns:

number of IDs / feature vectors

getVector

float[] getVector(String id)

Parameters:

id - ID to get feature vector for

Returns:

feature vector for ID, or null if doesn't exist

setVector

void setVector(String id,
               float[] vector)

Sets the value of a feature vector for an ID. If no feature vector previously existed, it is considered a "recent" ID until the next retainRecentAndIDs(Collection) call.

Parameters:

id - ID to set feature vector for

vector - new feature vector

addAllIDsTo

void addAllIDsTo(Collection<String> allIDs)

Adds all IDs that are mapped to a feature vector to a given collection

Parameters:

allIDs - collection to add IDs to

removeAllIDsFrom

void removeAllIDsFrom(Collection<String> allIDs)

Removes all IDs that are mapped to a feature vector from a given collection

Parameters:

allIDs - collection to add IDs to

addAllRecentTo

void addAllRecentTo(Collection<String> allRecent)

Add all recently set IDs to the given collection

Parameters:

allRecent - collection to add IDs to

retainRecentAndIDs

void retainRecentAndIDs(Collection<String> newModelIDs)

Given IDs that are part of a new model, and whose values are going to be sent later, retain only IDs that are also in the new model (or have been recently seen -- possibly since last model was built), and remove the rest.

Parameters:

newModelIDs - new model IDs

getVTV

double[] getVTV(boolean background)

Parameters:

background - if true, a hint that this potentially expensive computation may be deprioritized and need not use all available resources to compute

Returns:

considering the feature vectors as the rows of a matrix V, this computes V^T * V, as a dense lower-triangular matrix, represented in BLAS 'packed' form, which is column-major.