numpy.arccosh#

numpy.arccosh(x,/,out=None,*,where=True,casting='same_kind',order='K',dtype=None,subok=True[,signature])=<ufunc'arccosh'>#

Inverse hyperbolic cosine, element-wise.

Parameters:
xarray_like

Input array.

outndarray, None, or tuple of ndarray and None, optional

A location into which the result is stored. If provided, it must havea shape that the inputs broadcast to. If not provided or None,a freshly-allocated array is returned. A tuple (possible only as akeyword argument) must have length equal to the number of outputs.

wherearray_like, optional

This condition is broadcast over the input. At locations where thecondition is True, theout array will be set to the ufunc result.Elsewhere, theout array will retain its original value.Note that if an uninitializedout array is created via the defaultout=None, locations within it where the condition is False willremain uninitialized.

**kwargs

For other keyword-only arguments, see theufunc docs.

Returns:
arccoshndarray

Array of the same shape asx.This is a scalar ifx is a scalar.

Notes

arccosh is a multivalued function: for eachx there are infinitelymany numbersz such thatcosh(z) = x. The convention is to return thez 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, ityieldsnan and sets theinvalid floating point error flag.

For complex-valued input,arccosh is a complex analytical function thathas a branch cut[-inf, 1] and is continuous from above on it.

References

[1]

M. Abramowitz and I.A. Stegun, “Handbook of Mathematical Functions”,10th printing, 1964, pp. 86.https://personal.math.ubc.ca/~cbm/aands/page_86.htm

[2]

Wikipedia, “Inverse hyperbolic function”,https://en.wikipedia.org/wiki/Arccosh

Examples

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