numpy.arccosh(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj]) = <ufunc 'arccosh'>
Inverse hyperbolic cosine, element-wise.
Parameters: |
x : array_like Input array. out : ndarray, None, or tuple of ndarray and None, optional A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or where : array_like, optional Values of True indicate to calculate the ufunc at that position, values of False indicate to leave the value in the output alone. **kwargs For other keyword-only arguments, see the ufunc docs. |
---|---|
Returns: |
arccosh : ndarray Array of the same shape as |
arccosh
is a multivalued function: for each x
there are infinitely many numbers z
such that cosh(z) = x
. The convention is to return the z
whose imaginary part lies in [-pi, pi]
and the real part in [0, inf]
.
For real-valued input data types, arccosh
always returns real output. For each value that cannot be expressed as a real number or infinity, it yields nan
and sets the invalid
floating point error flag.
For complex-valued input, arccosh
is a complex analytical function that has a branch cut [-inf, 1]
and is continuous from above on it.
[R3] | M. Abramowitz and I.A. Stegun, “Handbook of Mathematical Functions”, 10th printing, 1964, pp. 86. http://www.math.sfu.ca/~cbm/aands/ |
[R4] | Wikipedia, “Inverse hyperbolic function”, http://en.wikipedia.org/wiki/Arccosh |
>>> np.arccosh([np.e, 10.0]) array([ 1.65745445, 2.99322285]) >>> np.arccosh(1) 0.0
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https://docs.scipy.org/doc/numpy-1.14.2/reference/generated/numpy.arccosh.html