numpy.emath.arctanh#
- emath.arctanh(x)[source]#
Compute the inverse hyperbolic tangent of x.
Return the “principal value” (for a description of this, see
numpy.arctanh
) ofarctanh(x)
. For real x such thatabs(x) < 1
, this is a real number. If abs(x) > 1, or if x is complex, the result is complex. Finally, x = 1 returns``inf`` andx=-1
returns-inf
.- Parameters:
- xarray_like
The value(s) whose arctanh is (are) required.
- Returns:
- outndarray or scalar
The inverse hyperbolic tangent(s) of the x value(s). If x was a scalar so is out, otherwise an array is returned.
See also
Notes
For an arctanh() that returns
NAN
when real x is not in the interval(-1,1)
, usenumpy.arctanh
(this latter, however, does return +/-inf forx = +/-1
).Examples
>>> np.set_printoptions(precision=4)
>>> np.emath.arctanh(0.5) 0.5493061443340549
>>> from numpy.testing import suppress_warnings >>> with suppress_warnings() as sup: ... sup.filter(RuntimeWarning) ... np.emath.arctanh(np.eye(2)) array([[inf, 0.], [ 0., inf]]) >>> np.emath.arctanh([1j]) array([0.+0.7854j])