Source code for monty.math
# coding: utf-8
from __future__ import division, unicode_literals, absolute_import
"""
Addition math functions.
"""
__author__ = 'Shyue Ping Ong'
__copyright__ = 'Copyright 2013, The Materials Virtual Lab'
__version__ = '0.1'
__maintainer__ = 'Shyue Ping Ong'
__email__ = 'ongsp@ucsd.edu'
__date__ = '10/28/14'
import math
[docs]def nCr(n, r):
"""
Calculates nCr.
Args:
n (int): total number of items.
r (int): items to choose
Returns:
nCr.
"""
f = math.factorial
return int(f(n) / f(r) / f(n-r))
[docs]def nPr(n, r):
"""
Calculates nPr.
Args:
n (int): total number of items.
r (int): items to permute
Returns:
nPr.
"""
f = math.factorial
return int(f(n) / f(n-r))