de.lmu.ifi.dbs.elki.data.projection.random

Class SimplifiedRandomHyperplaneProjectionFamily.SignedProjection

java.lang.Object

de.lmu.ifi.dbs.elki.data.projection.random.SimplifiedRandomHyperplaneProjectionFamily.SignedProjection

All Implemented Interfaces:

RandomProjectionFamily.Projection

Enclosing class:

SimplifiedRandomHyperplaneProjectionFamily

private static class SimplifiedRandomHyperplaneProjectionFamily.SignedProjection
extends java.lang.Object
implements RandomProjectionFamily.Projection

Fast projection class, using booleans to represent +-1 matrix entries. Optimized for sparse multiplications, thus we are using a column-row layout.

Author:

Erich Schubert

Field Summary

Fields

Modifier and Type	Field and Description
private double[]	buf Shared buffer to use during projections.
private int	k Output dimensionality
(package private) boolean[][]	mat Projection matrix.

Constructor Summary

Constructors

Constructor and Description
SignedProjection(int dim, int k, java.util.Random random) Constructor.

Method Summary

Modifier and Type	Method and Description
int	getOutputDimensionality() Get the output dimensionality.
double[]	project(NumberVector in) Project a single vector.
double[]	project(NumberVector vec, double[] ret) Project a single vector, into the given buffer.
private double[]	projectDense(NumberVector in, double[] ret) Slower version, for dense multiplication.

Methods inherited from class java.lang.Object

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

Field Detail

mat

boolean[][] mat

Projection matrix.

k

private int k

Output dimensionality

buf

private double[] buf

Shared buffer to use during projections.

Constructor Detail

SignedProjection

public SignedProjection(int dim,
                        int k,
                        java.util.Random random)

Constructor.

Parameters:

dim - Input dimensionality

k - Output dimensionality

random - Random generator

Method Detail

project

public double[] project(NumberVector in)

Description copied from interface: RandomProjectionFamily.Projection

Project a single vector.

Specified by:

project in interface RandomProjectionFamily.Projection

Parameters:

in - Input vector

Returns:

Projected vector

project

public double[] project(NumberVector vec,
                        double[] ret)

Description copied from interface: RandomProjectionFamily.Projection

Project a single vector, into the given buffer.

Specified by:

project in interface RandomProjectionFamily.Projection

Parameters:

vec - Input vector

ret - Output buffer

Returns:

buffer

projectDense

private double[] projectDense(NumberVector in,
                              double[] ret)

Slower version, for dense multiplication.

Parameters:

in - Input vector

Returns:

Projected data.

getOutputDimensionality

public int getOutputDimensionality()

Description copied from interface: RandomProjectionFamily.Projection

Get the output dimensionality.

Specified by:

getOutputDimensionality in interface RandomProjectionFamily.Projection

Returns:

Output dimensionality