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bundles / scipy latest / scipy / special / _basic / perm

function

scipy.special._basic:perm

source: /scipy/special/_basic.py :2565

Signature

def   perm ( N ,  k ,  exact = False )

Summary

Permutations of N things taken k at a time, i.e., k-permutations of N.

Extended Summary

It's also known as "partial permutations".

Parameters

N : int, ndarray

Number of things.

k : int, ndarray

Number of elements taken.

exact : bool, optional

If True, calculate the answer exactly using long integer arithmetic (N and k must be scalar integers). If False, a floating point approximation is calculated (more rapidly) using poch. Default is False.

Returns

val : int, ndarray

The number of k-permutations of N.

Notes

  • Array arguments accepted only for exact=False case.

  • If k > N, N < 0, or k < 0, then a 0 is returned.

Examples

import numpy as np
from scipy.special import perm
k = np.array([3, 4])
n = np.array([10, 10])
✓
perm(n, k)
✗
perm(10, 3, exact=True)
✓

Aliases

  • scipy.special.perm

Referenced by

This package