`numpy.lib.scimath:arccos`

source: build-install/usr/lib/python3.14/site-packages/numpy/lib/_scimath_impl.py:494

Signature

def arccos(x)

Summary

Compute the inverse cosine of x.

Extended Summary

Return the "principal value" (for a description of this, see numpy.arccos) of the inverse cosine of x. For real x such that abs(x) <= 1, this is a real number in the closed interval $[0, π]$ . Otherwise, the complex principle value is returned.

Parameters

x : array_like or scalar: The value(s) whose arccos is (are) required.

Returns

out : ndarray or scalar: The inverse cosine(s) of the x value(s). If x was a scalar, so is out, otherwise an array object is returned.

Notes

For an arccos() that returns NAN when real x is not in the interval [-1,1], use numpy.arccos.

Examples

import numpy as np
np.set_printoptions(precision=4)

✓

np.emath.arccos(1) # a scalar is returned

✗

np.float64(0.0)

np.emath.arccos([1,2])

✓

array([0.-0.j   , 0.-1.317j])

Aliases

numpy.emath.arccos