org.grouplens.lenskit.transform.quantize

Class ValueArrayQuantizer

java.lang.Object

org.grouplens.lenskit.transform.quantize.ValueArrayQuantizer

All Implemented Interfaces:

Serializable, Quantizer

Direct Known Subclasses:

PreferenceDomainQuantizer

@Shareable
public class ValueArrayQuantizer
extends Object
implements Quantizer, Serializable

Abstract quantizer implementation using a pre-generated array of possible values. Values are quantized to their closest discrete possibility.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected mikera.vectorz.impl.ImmutableVector	values The values to quantize to.

Constructor Summary

Constructors

Constructor and Description
ValueArrayQuantizer(double[] vs) Construct a new quantizer using the specified array of values.
ValueArrayQuantizer(mikera.vectorz.impl.ImmutableVector vs)

Method Summary

Modifier and Type	Method and Description
int	getCount() Get the number of discrete values the output can take.
double	getIndexValue(int i) Get the value corresponding to a quantized value, based on the index into the list of possible values.
mikera.vectorz.impl.ImmutableVector	getValues() Get the possible values into which this quantizer will map input values.
int	index(double val) Convert a value into a discrete, quantized value.
double	quantize(double val) Convert a value into a quantized value, returning the quantized value.

Methods inherited from class java.lang.Object

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

Field Detail

values

protected final mikera.vectorz.impl.ImmutableVector values

The values to quantize to. Subclasses must not modify this array after the object has been constructed.

Constructor Detail

ValueArrayQuantizer

public ValueArrayQuantizer(double[] vs)

Construct a new quantizer using the specified array of values.

Parameters:

vs - The discrete values to quantize to.

ValueArrayQuantizer

public ValueArrayQuantizer(mikera.vectorz.impl.ImmutableVector vs)

Method Detail

getValues

public mikera.vectorz.impl.ImmutableVector getValues()

Description copied from interface: Quantizer

Get the possible values into which this quantizer will map input values. These are the values corresponding to each “bin” into which the quantizer will put values.

Specified by:

getValues in interface Quantizer

Returns:

The values of the discrete bins.

getCount

public int getCount()

Description copied from interface: Quantizer

Get the number of discrete values the output can take.

Specified by:

getCount in interface Quantizer

Returns:

The number of possible discrete values.

getIndexValue

public double getIndexValue(int i)

Description copied from interface: Quantizer

Get the value corresponding to a quantized value, based on the index into the list of possible values.

Specified by:

getIndexValue in interface Quantizer

Parameters:

i - The quantized value number, in the range [0,n) where n is the number of possible discrete values (see Quantizer.getCount()).

Returns:

The value corresponding to quantum i.

index

public int index(double val)

Description copied from interface: Quantizer

Convert a value into a discrete, quantized value.

Specified by:

index in interface Quantizer

Parameters:

val - A value to quantize.

Returns:

The index of the discrete value to which val is mapped.

quantize

public double quantize(double val)

Description copied from interface: Quantizer

Convert a value into a quantized value, returning the quantized value.

Specified by:

quantize in interface Quantizer

Parameters:

val - A value to quantize.

Returns:

The quantized value.