mars.tensor.arctanh¶

mars.tensor.
arctanh
(x, out=None, where=None, **kwargs)[source]¶ Inverse hyperbolic tangent elementwise.
 x : array_like
 Input tensor.
 out : Tensor, None, or tuple of Tensor 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 freshlyallocated tensor 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.
**kwargs
 out : Tensor
 Array of the same shape as x.
arctanh is a multivalued function: for each x there are infinitely many numbers z such that tanh(z) = x. The convention is to return the z whose imaginary part lies in [pi/2, pi/2].
For realvalued input data types, arctanh 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 complexvalued input, arctanh is a complex analytical function that has branch cuts [1, inf] and [1, inf] and is continuous from above on the former and from below on the latter.
The inverse hyperbolic tangent is also known as atanh or
tanh^1
.[1] M. Abramowitz and I.A. Stegun, “Handbook of Mathematical Functions”, 10th printing, 1964, pp. 86. http://www.math.sfu.ca/~cbm/aands/ [2] Wikipedia, “Inverse hyperbolic function”, http://en.wikipedia.org/wiki/Arctanh >>> import mars.tensor as mt
>>> mt.arctanh([0, 0.5]).execute() array([ 0. , 0.54930614])