numpy.arccosh()

numpy.arccosh(x[, out]) =

Inverse hyperbolic cosine, element-wise.

Parameters:

Parameters:	x : array_like Input array. out : ndarray, optional Array of the same shape as `x`, to store results in. See `doc.ufuncs` (Section ?Output arguments?) for details.
Returns:	arccosh : ndarray Array of the same shape as `x`.

x : array_like

Input array.

out : ndarray, optional

Array of the same shape as x, to store results in. See doc.ufuncs (Section ?Output arguments?) for details.

Returns:

arccosh : ndarray

Array of the same shape as x.

Notes

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.

References

[R2]	M. Abramowitz and I.A. Stegun, ?Handbook of Mathematical Functions?, 10th printing, 1964, pp. 86. http://www.math.sfu.ca/~cbm/aands/

[R3]	Wikipedia, ?Inverse hyperbolic function?, http://en.wikipedia.org/wiki/Arccosh

Examples

>>> np.arccosh([np.e, 10.0])
array([ 1.65745445,  2.99322285])
>>> np.arccosh(1)
0.0

Links:

https://docs.scipy.org/doc/numpy-1.11.0/reference/generated/numpy.arccosh.html

doc_NumPy

2017-01-10 18:12:40

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