Power series representations in Python. Based on http://doc.cat-v.org/bell_labs/squinting_at_power_series/squint.pdf.

This is a Python implementation of the pseudocode in the above paper by Doug McIlroy, with some additional operations added that the paper did not include. I have also added a module that uses the power series implementation to compute functions represented by series, with simple convergence testing.

Back when McIlroy's paper was first written, he noted that programming languages with the key features needed for such an implementation were not in common use. Things are certainly different now; the Python implementation given here is a fairly straightforward expression of the algorithms in the paper, and it's fast, but McIlroy put a Haskell implementation on the web in 2007 that's way more compact; see here:

http://www.cs.dartmouth.edu/~doug/powser.html

All of the Haskell definitions there are one-liners. But I like Python, and AFAIK no one has done an implementation of this stuff in Python, so there you are. :-)

See the docstrings in powerseries.py and powerfunc.py for more information.

Released under the open source MIT license: http://www.opensource.org/licenses/MIT

Copyright (C) 2011 Peter A. Donis.

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