from brian2 import arccosh)
arccosh(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj])¶
Inverse hyperbolic cosine, element-wise.
x : array_like
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
None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs.
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.
For other keyword-only arguments, see the ufunc docs.
arccosh : ndarray
Array of the same shape as
x. This is a scalar if
xis a scalar.
arccosh()is a multivalued function: for each
xthere are infinitely many numbers
cosh(z) = x. The convention is to return the
zwhose imaginary part lies in
[-pi, pi]and the real part in
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
nanand sets the
invalidfloating 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.
[R13] M. Abramowitz and I.A. Stegun, “Handbook of Mathematical Functions”, 10th printing, 1964, pp. 86. http://www.math.sfu.ca/~cbm/aands/ [R14] 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