factoradic 1.0.3

Status

Installation

The factoradic package is available on the Python Package Index (PyPI):

The package supports Python 3 only. To install:

$ pip install factoradic

Python Interface

For full help:

>>> import factoradic
>>> help(factoradic)

In the meantime, here are some highlights.

To convert from an integer to factoradic use to_factoradic():

>>> factoradic.to_factoradic(1337)
[0, 1, 2, 2, 0, 5, 1]

The result is the list of coefficients where the factorial of each zero-based index gives a place value, and the item at that index is the coefficient by with the place value is to be multiplied. The elements are from least-significant to most-significant. Since the coefficient at any index must be less that or equal to the index, the coefficient at index 0 is always 0.

To convert from factoradic use from_factoradic():

>>> factoradic.from_factoradic([0, 1, 2, 2, 0, 5, 1])
1337

Command-Line Interface

There’s also a handy command-line interface. Run factoradic --help to see a list of commands:

$ factoradic --help
Factoradic.

Convert to and from the factorial number system.

Usage:
  factoradic from-integer <integer> [--expression]
  factoradic to-integer <coefficient-0> [<coefficient-1> [<coefficient-n>...]]

Options:
  -e --expression  Show as a mathematical expression.

To convert from an integer to factoradic, use the from-integer subcommand:

$ factoradic from-integer 1729
0 1 0 0 2 2 2

The coefficients are reported from least-significant to most-significant. The see the results as a math expression, specify the --expression flag:

$ factoradic from-integer 1729 --expression
2*6! + 2*5! + 2*4! + 0*3! + 0*2! + 1*1! + 0*0!

To convert from factoradic representation use the to-integer subcommand, specifying the coefficients from least-significant to most-significant:

$ factoradic to-integer 0 1 0 0 2 2 2
1729