boreaso / pcfg-toolbox

A Probabilistic Context-Free Grammar toolbox for Java

A Probabilistic Context-Free Grammar (PCFG) toolbox for Java

This toolbox contains classes to represent PCFGs and two parsers: a simple parser based on dynamic programming that requires the PCFG to be in Chomsky Normal Form (CNF), and the Earley parser.

The toolbox includes various utilities, including automatically transforming a PCFG to CNF (the algorithm's principle is presented in pcfg_cnf.pdf), saving and restoring grammars in human-readable format and in a custom format, generating parse trees, computing probabilities of sub-trees (either by multiplication or addition), and generating Graphviz DOT code to visualize the trees.

The Javadoc is available here.

Help to use the toolbox with MATLAB is available here.

This project uses the Apache Commons Math.