Where's Yr Head At

Where's Yr Head At (WYHA) is an implementation of a unlabeled dependency parser using arc-hybrid transitions, a dynamic oracle, the averaged perceptron classifier, and greedy search.

The arc-hybrid transition system was originally described by Kuhlmann et al. 2011. The dynamic oracle framework was proposed by Goldberg & Nivre 2013. The classifier features are based on those proposed by Matthew Honnibal in a recent blog post, though I have attempted to correct what I believe to be a few typos there.

WYHA is not designed to be particularly fast or to outperform state of the art systems. Rather, the focus is on clean design of the sort useful for teaching and research.

WYHA has been tested on CPython 3.4 and PyPy3 (2.4.0, corresponding to Python 3.2; this also requires the 3rd-party library enum34). It requires three third-party packages: nltk and jsonpickle from PyPI and my own nlup library, available from GitHub; see requirements.txt for the versions used for testing.

Usage

python -m wheresyrheadat [-h] [-v | -V] (-r READ | -t TRAIN)
                         (-e EVALUATE | -p PARSE | -w WRITE)
                         [-E EPOCHS]

A greedy arc-hybrid dependency parser

optional arguments:

-h, --help                          show this help message and exit
-v, --verbose                       enable verbose output
-V, --really-verbose                enable even more verbose output
-r READ, --read READ                read in serialized model
-t TRAIN, --train TRAIN             training data
-e EVALUATE, --evaluate EVALUATE    evaluate on labeled data
-p PARSE, --parse PARSE             parse tagged sentences
-w WRITE, --write WRITE             write out serialized model
-E EPOCHS, --epochs EPOCHS          # of epochs (default: 10)

For anything else, UTSL.

License

MIT License (BSD-like); see source.

What's with the name?

A transition-based dependency parser is fundamentally trying to answer the question "where's your head at?" for every word. The name is also a tribute to electronic music duo Basement Jaxx's 2001 hit single "Where's Your Head At".

Bugs, comments?

Contact Kyle Gorman.

References

M. Kuhlmann, C. Gómez-Rodríguez, and G. Satta. 2011. Dynamic programming algorithms for transition-based dependency parsers. In ACL, 673-682.

Y. Goldberg and J. Nivre. 2013. Training deterministic parsers with non-deterministic oracles. Transactions of the Association for Computational Linguistics 1: 403-414.