numpy.emath.arccos#
- emath.arccos(x)[source]#
Compute the inverse cosine of x.
Return the “principal value” (for a description of this, see
numpy.arccos
) of the inverse cosine of x. For real x such that abs(x) <= 1, this is a real number in the closed interval \([0, \pi]\). Otherwise, the complex principle value is returned.- Parameters:
- xarray_like or scalar
The value(s) whose arccos is (are) required.
- Returns:
- outndarray or scalar
The inverse cosine(s) of the x value(s). If x was a scalar, so is out, otherwise an array object is returned.
See also
Notes
For an arccos() that returns
NAN
when real x is not in the interval[-1,1]
, usenumpy.arccos
.Examples
>>> np.set_printoptions(precision=4)
>>> np.emath.arccos(1) # a scalar is returned 0.0
>>> np.emath.arccos([1,2]) array([0.-0.j , 0.-1.317j])