co.py.cat

An implementation of Douglas Hofstadter's Copycat algorithm. The Copycat algorithm is explained on Wikipedia, and that page has many links for deeper reading.

This implementation is a copycat of Scott Boland's Java implementation. The original Java-to-Python translation work was done by J Alan Brogan (@jalanb on GitHub). The Java version has a GUI similar to the original Lisp; this Python version has no GUI code built in but can be incorporated into a larger GUI program.

J Alan Brogan writes:

In cases where I could not grok the Java implementation easily, I took ideas from the LISP implementation, or directly from Melanie Mitchell's book "Analogy-Making as Perception".

Running the command-line program

To clone the repo locally, run these commands:

$ git clone https://github.com/Quuxplusone/co.py.cat.git
$ cd co.py.cat/copycat
$ python main.py abc abd ppqqrr 10

The script takes three or four arguments. The first two are a pair of strings with some change, for example "abc" and "abd". The third is a string which the script should try to change analogously. The fourth (which defaults to "1") is a number of iterations.

This might produce output such as

ppqqss: 6 (avg time 869.0, avg temp 23.4)
ppqqrs: 4 (avg time 439.0, avg temp 37.3)

The first number indicates how many times Copycat chose that string as its answer; higher means "more obvious". The last number indicates the average final temperature of the workspace; lower means "more elegant".

Running the curses interface

Follow the instructions to clone the repo as above, but then run curses_main instead of main:

$ git clone https://github.com/Quuxplusone/co.py.cat.git
$ cd co.py.cat/copycat
$ python curses_main.py abc abd ppqqrr

This script takes only three arguments. The first two are a pair of strings with some change, for example "abc" and "abd". The third is a string which the script should try to change analogously. The number of iterations is always implicitly "infinite". To kill the program, hit Ctrl+C.

Installing the module

To install the Python module and get started with it, run these commands:

$ pip install -e git+git://github.com/Quuxplusone/co.py.cat.git#egg=copycat
$ python
>>> from copycat import Copycat
>>> Copycat().run('abc', 'abd', 'ppqqrr', 10)
{'ppqqrs': {'count': 4, 'avgtime': 439, 'avgtemp': 37.3}, 'ppqqss': {'count': 6, 'avgtime': 869, 'avgtemp': 23.4}}

The result of run is a dict containing the same information as was printed by main.py above.