cc.mallet.types
Class Instance

java.lang.Object
  cc.mallet.types.Instance

All Implemented Interfaces:

AlphabetCarrying, java.io.Serializable, java.lang.Cloneable

public class Instance
extends java.lang.Object
implements java.io.Serializable, AlphabetCarrying, java.lang.Cloneable

A machine learning "example" to be used in training, testing or performance of various machine learning algorithms.

An instance contains four generic fields of predefined name: "data", "target", "name", and "source". "Data" holds the data represented `by the instance, "target" is often a label associated with the instance, "name" is a short identifying name for the instance (such as a filename), and "source" is human-readable sourceinformation, (such as the original text).

Each field has no predefined type, and may change type as the instance is processed. For example, the data field may start off being a string that represents a file name and then be processed by a Pipe into a CharSequence representing the contents of the file, and eventually to a feature vector holding indices into an Alphabet holding words found in the file. It is up to each pipe which fields in the Instance it modifies; the most common case is that the pipe modifies the data field.

Generally speaking, there are two modes of operation for Instances. (1) An instance gets created and passed through a Pipe, and the resulting data/target/name/source fields are used. This is generally done for training instances. (2) An instance gets created with raw values in its slots, then different users of the instance call newPipedCopy() with their respective different pipes. This might be done for test instances at "performance" time.

Rather than store an Alphabet in the Instance, we obtain it through the Pipe instance variable, because the Pipe also indicates where the data came from and how to interpret the Alphabet.

Instances can be made immutable if locked. Although unlocked Instances are mutable, typically the only code that changes the values in the four slots is inside Pipes.

Note that constructing an instance with a pipe argument means "Construct the instance and then run it through the pipe". InstanceList uses this method when adding instances through a pipeInputIterator.

Author:

Andrew McCallum mccallum@cs.umass.edu

See Also:

Pipe, Alphabet, InstanceList, Serialized Form

Field Summary

protected java.lang.Object	data
protected java.lang.Object	name
protected java.lang.Object	source
protected java.lang.Object	target

Constructor Summary

Instance(java.lang.Object data, java.lang.Object target, java.lang.Object name, java.lang.Object source)
In certain unusual circumstances, you might want to create an Instance without sending it through a pipe.

Method Summary

boolean	alphabetsMatch(AlphabetCarrying object)
void	clearSource()
java.lang.Object	clone()
Alphabet	getAlphabet()
Alphabet[]	getAlphabets()
java.lang.Object	getData()
Alphabet	getDataAlphabet()
Labeling	getLabeling()
java.lang.Object	getName()
double	getNumericProperty(java.lang.String key)
PropertyList	getProperties() Deprecated.
java.lang.Object	getProperty(java.lang.String key)
java.lang.Object	getSource()
java.lang.Object	getTarget()
Alphabet	getTargetAlphabet()
boolean	hasProperty(java.lang.String key)
boolean	isLocked()
void	lock()
void	setData(java.lang.Object d)
void	setLabeling(Labeling l)
void	setName(java.lang.Object n)
void	setNumericProperty(java.lang.String key, double value)
void	setProperty(java.lang.String key, java.lang.Object value)
void	setPropertyList(PropertyList p) Deprecated.
void	setSource(java.lang.Object s)
void	setTarget(java.lang.Object t)
Instance	shallowCopy()
void	unLock()

Methods inherited from class java.lang.Object

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

Field Detail

data

protected java.lang.Object data

target

protected java.lang.Object target

name

protected java.lang.Object name

source

protected java.lang.Object source

Constructor Detail

Instance

public Instance(java.lang.Object data,
                java.lang.Object target,
                java.lang.Object name,
                java.lang.Object source)

In certain unusual circumstances, you might want to create an Instance without sending it through a pipe.

Method Detail

getData

public java.lang.Object getData()

getTarget

public java.lang.Object getTarget()

getName

public java.lang.Object getName()

getSource

public java.lang.Object getSource()

getDataAlphabet

public Alphabet getDataAlphabet()

getTargetAlphabet

public Alphabet getTargetAlphabet()

getAlphabet

public Alphabet getAlphabet()

Specified by:

getAlphabet in interface AlphabetCarrying

getAlphabets

public Alphabet[] getAlphabets()

Specified by:

getAlphabets in interface AlphabetCarrying

alphabetsMatch

public boolean alphabetsMatch(AlphabetCarrying object)

isLocked

public boolean isLocked()

lock

public void lock()

unLock

public void unLock()

getLabeling

public Labeling getLabeling()

setData

public void setData(java.lang.Object d)

setTarget

public void setTarget(java.lang.Object t)

setLabeling

public void setLabeling(Labeling l)

setName

public void setName(java.lang.Object n)

setSource

public void setSource(java.lang.Object s)

clearSource

public void clearSource()

shallowCopy

public Instance shallowCopy()

clone

public java.lang.Object clone()

Overrides:

clone in class java.lang.Object

setProperty

public void setProperty(java.lang.String key,
                        java.lang.Object value)

setNumericProperty

public void setNumericProperty(java.lang.String key,
                               double value)

getProperties

@Deprecated
public PropertyList getProperties()

Deprecated.

setPropertyList

@Deprecated
public void setPropertyList(PropertyList p)

Deprecated.

getProperty

public java.lang.Object getProperty(java.lang.String key)

getNumericProperty

public double getNumericProperty(java.lang.String key)

hasProperty

public boolean hasProperty(java.lang.String key)