Package elki.data.projection.random

Class SimplifiedRandomHyperplaneProjectionFamily.SignedProjection

java.lang.Object

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

Method Summary

Modifier and Type	Method	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