edu.stanford.nlp.cluster
Class HiddenState

java.lang.Object
  |
  +--edu.stanford.nlp.cluster.SimpleCluster
        |
        +--edu.stanford.nlp.cluster.HiddenState

All Implemented Interfaces:

Cloneable, Cluster

public class HiddenState

extends SimpleCluster

Data Structure for clusters in LSSA.

HiddenState is a subclass of SimpleCluster which is specifically tailored towards HMM-based clustering methods. This differs from SoftCluster in that it stores an array of transition probabilities from this hidden class to each of the other hidden classes. In addition, it stores growable forward_trellis and backward_trellis Arrays that give the probability of the hidden state at each time step t given an observation sequence O.

Field Summary

Fields inherited from class edu.stanford.nlp.cluster.SimpleCluster

index, mean, nd, nt, pr_d_z, pr_w_z, pr_z, scatter

Constructor Summary

HiddenState(int num_terms, int num_docs, int num_states)
Constructor: allocates memory for arrays, but does not initializes values

HiddenState(int num_terms, int num_docs, int num_states, int i)

Method Summary

Object	clone() overwrites Cluster.clone() so that all the additional structures in HiddenState are also copied to its clone
ScientificNotationDouble	get_a(int j)
ScientificNotationDouble	get_alpha(int d, int t)
ScientificNotationDouble	get_b(int w)
ScientificNotationDouble	get_beta(int d, int t)
ScientificNotationDouble	get_pi()
void	initialize_alpha(Array O)
void	initialize_alpha(DataCollection db) allocates memory for alpha[][]
void	initialize_alpha(int d, Array O) allocates memory for alpha[d]
void	initialize_beta(Array O)
void	initialize_beta(DataCollection db) allocates memory for beta[][]
void	initialize_beta(int d, Array O) allocates memory for beta[d]
void	initialize_transition_probs() Initialize: initializes random values pr_transition[], an array of transition probabilities from this state to all the other states Note: does not initialize values for pi (the probability that this class is the initial state) because the value for pi depends on the value for pi of all the other clusters, since sum_over_z(pi)=1 The value for pi is set in LSSA
void	print_pr_transition()
void	print_trellis()
void	set_a(int j, ScientificNotationDouble value)
void	set_alpha(int d, int t, ScientificNotationDouble value)
void	set_alpha(ScientificNotationDouble[][] al)
void	set_b(int w, ScientificNotationDouble value)
void	set_beta(int d, int t, ScientificNotationDouble value)
void	set_beta(ScientificNotationDouble[][] bet)
void	set_pi(ScientificNotationDouble p)
String	toString(DataCollection dbm) Returns String representation of Cluster prints default number of features and data.
String	toXMLString(int tnf, int tnd, DataCollection dbm) Returns XML String representation of Cluster

Methods inherited from class edu.stanford.nlp.cluster.SimpleCluster

clearData, equals, evaluateIntraSimilarity, evaluateWeightedMean, get_pr_d_z, get_pr_d_z, get_pr_w_z, get_pr_w_z, get_pr_z, getIndex, getIntraSimilarity, getMean, set_pr_d_z, set_pr_d_z, set_pr_w_z, set_pr_w_z, set_pr_z, setIndex, toString, toXMLString

Methods inherited from class java.lang.Object

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

Constructor Detail

HiddenState

public HiddenState(int num_terms,
                   int num_docs,
                   int num_states)

Constructor: allocates memory for arrays, but does not initializes values

HiddenState

public HiddenState(int num_terms,
                   int num_docs,
                   int num_states,
                   int i)

Method Detail

initialize_transition_probs

public void initialize_transition_probs()

Initialize: initializes random values pr_transition[], an array of transition probabilities from this state to all the other states Note: does not initialize values for pi (the probability that this class is the initial state) because the value for pi depends on the value for pi of all the other clusters, since sum_over_z(pi)=1 The value for pi is set in LSSA

initialize_alpha

public void initialize_alpha(Array O)

initialize_beta

public void initialize_beta(Array O)

initialize_alpha

public void initialize_alpha(DataCollection db)

allocates memory for alpha[][]

initialize_beta

public void initialize_beta(DataCollection db)

allocates memory for beta[][]

initialize_alpha

public void initialize_alpha(int d,
                             Array O)

allocates memory for alpha[d]

initialize_beta

public void initialize_beta(int d,
                            Array O)

allocates memory for beta[d]

get_alpha

public ScientificNotationDouble get_alpha(int d,
                                          int t)

get_beta

public ScientificNotationDouble get_beta(int d,
                                         int t)

get_a

public ScientificNotationDouble get_a(int j)

print_pr_transition

public void print_pr_transition()

get_b

public ScientificNotationDouble get_b(int w)

set_alpha

public void set_alpha(ScientificNotationDouble[][] al)

set_beta

public void set_beta(ScientificNotationDouble[][] bet)

set_alpha

public void set_alpha(int d,
                      int t,
                      ScientificNotationDouble value)

set_beta

public void set_beta(int d,
                     int t,
                     ScientificNotationDouble value)

set_a

public void set_a(int j,
                  ScientificNotationDouble value)

set_b

public void set_b(int w,
                  ScientificNotationDouble value)

set_pi

public void set_pi(ScientificNotationDouble p)

get_pi

public ScientificNotationDouble get_pi()

clone

public Object clone()

overwrites Cluster.clone() so that all the additional structures in HiddenState are also copied to its clone

Specified by:

clone in interface Cluster

Overrides:

clone in class SimpleCluster

toString

public String toString(DataCollection dbm)

Description copied from interface: Cluster

Returns String representation of Cluster prints default number of features and data. (normally 20)

Specified by:

toString in interface Cluster

Overrides:

toString in class SimpleCluster

print_trellis

public void print_trellis()

toXMLString

public String toXMLString(int tnf,
                          int tnd,
                          DataCollection dbm)

Description copied from interface: Cluster

Returns XML String representation of Cluster

Specified by:

toXMLString in interface Cluster

Overrides:

toXMLString in class SimpleCluster

Parameters:

tnf - top n features. prints top tnf features with largest probabilities

tnd - top n datums. prints top tnd datums with largest probabilities