In file ../include/EST_SCFG.h:

class EST_SCFG

A class representing a stochastic context free grammar (SCFG).

Inheritance:

Public Methods

	Constructor and initialisation functions EST_SCFG (LISP rules) Initialize from a set of rules
	utility functions void set_rules (LISP rules) Set (or reset) rules from external source after construction LISP get_rules () Return rules as LISP list SCFGRuleList rules The rules themselves void find_terms_nonterms (EST_StrList &nt, EST_StrList &t, LISP rules) Find the terminals and nonterminals in the given grammar, adding them to the appropriate given string lists EST_String nonterminal (int p) const Convert nonterminal index to string form EST_String terminal (int m) const Convert terminal index to string form int nonterminal (const EST_String &p) const Convert nonterminal string to index int terminal (const EST_String &m) const Convert terminal string to index int num_nonterminals () const Number of nonterminals int num_terminals () const Number of terminals double prob_B (int p, int q, int r) const The rule probability of given binary rule double prob_U (int p, int m) const The rule probability of given unary rule void set_rule_prob_cache () (re-)set rule probability caches
	file i/o functions EST_read_status load (const EST_String &filename) Load grammar from named file EST_write_status save (const EST_String &filename) Save current grammar to named file

Documentation

A class representing a stochastic context free grammar (SCFG).

This class includes the representation of the grammar itself and methods for training and testing it against some corpus.

At presnet of grammars in Chomsky Normal Form are supported. That is rules may be binary or unary. If binary the mother an two daughters are nonterminals, if unary the mother must be nonterminal and daughter a terminal symbol.

The terminals and nonterminals symbol sets are derived automatically from the LISP representation of the rules at initialization time and are represented as EST_Discretes. The distinguished symbol is assumed to be the first mother of the first rule in the given grammar.

Constructor and initialisation functions

EST_SCFG(LISP rules)

Initialize from a set of rules

utility functions

void set_rules(LISP rules)

Set (or reset) rules from external source after construction

LISP get_rules()

Return rules as LISP list

SCFGRuleList rules

The rules themselves

void find_terms_nonterms(EST_StrList &nt, EST_StrList &t, LISP rules)

Find the terminals and nonterminals in the given grammar, adding them to the appropriate given string lists

EST_String nonterminal(int p) const

Convert nonterminal index to string form

EST_String terminal(int m) const

Convert terminal index to string form

int nonterminal(const EST_String &p) const

Convert nonterminal string to index

int terminal(const EST_String &m) const

Convert terminal string to index

int num_nonterminals() const

Number of nonterminals

int num_terminals() const

Number of terminals

double prob_B(int p, int q, int r) const

The rule probability of given binary rule

double prob_U(int p, int m) const

The rule probability of given unary rule

void set_rule_prob_cache()

(re-)set rule probability caches

file i/o functions

EST_read_status load(const EST_String &filename)

Load grammar from named file

EST_write_status save(const EST_String &filename)

Save current grammar to named file

Direct child classes:

EST_SCFG_traintest

Alphabetic index HTML hierarchy of classes or Java

This page is part of the Edinburgh Speech Tools Library documentation
Copyright University of Edinburgh 1997
Contact: speech_tools@cstr.ed.ac.uk