# scipy.special.comb

scipy.special.comb(N, k, exact=False, repetition=False)

  The number of combinations of N things taken k at a time.

  This is often expressed as “N choose k”.

  Parameters
    N int, ndarray

      Number of things.

    k int, ndarray

      Number of elements taken.

    exact bool, optional

      If exact is False, then floating point precision is used, otherwise exact long integer is computed.

    repetition bool, optional

      If repetition is True, then the number of combinations with repetition is computed.

  Returns
    val int, float, ndarray

      The total number of combinations.

  See also

  `binom`

    Binomial coefficient ufunc

  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

      >>> 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

scipy.special.keip_zeros scipy.special.perm