scipy.special.
comb#
- scipy.special.comb(N, k, *, exact=False, repetition=False)[source]#
The number of combinations of N things taken k at a time.
This is often expressed as “N choose k”.
- Parameters:
- Nint, ndarray
Number of things.
- kint, ndarray
Number of elements taken.
- exactbool, optional
For integers, if exact is False, then floating point precision is used, otherwise the result is computed exactly.
Deprecated since version 1.14.0:
exact=True
is deprecated for non-integer N and k and will raise an error in SciPy 1.16.0- repetitionbool, optional
If repetition is True, then the number of combinations with repetition is computed.
- Returns:
- valint, float, ndarray
The total number of combinations.
See also
binom
Binomial coefficient considered as a function of two real variables.
Notes
Array arguments accepted only for exact=False case.
If N < 0, or k < 0, then 0 is returned.
If k > N and repetition=False, then 0 is returned.
Examples
>>> import numpy as np >>> from scipy.special import comb >>> k = np.array([3, 4]) >>> n = np.array([10, 10]) >>> comb(n, k, exact=False) array([ 120., 210.]) >>> comb(10, 3, exact=True) 120 >>> comb(10, 3, exact=True, repetition=True) 220