mars.tensor.arctan¶

mars.tensor.
arctan
(x, out=None, where=None, **kwargs)[source]¶ Trigonometric inverse tangent, elementwise.
The inverse of tan, so that if
y = tan(x)
thenx = arctan(y)
.x : array_like 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
 Out has the same shape as x. Its real part is in
[pi/2, pi/2]
(arctan(+/inf)
returns+/pi/2
). It is a scalar if x is a scalar.
 arctan2 : The “four quadrant” arctan of the angle formed by (x, y)
 and the positive xaxis.
angle : Argument of complex values.
arctan is a multivalued function: for each x there are infinitely many numbers z such that tan(z) = x. The convention is to return the angle z whose real part lies in [pi/2, pi/2].
For realvalued input data types, arctan 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, arctan is a complex analytic function that has [1j, infj] and [1j, infj] as branch cuts, and is continuous from the left on the former and from the right on the latter.
The inverse tangent is also known as atan or tan^{1}.
Abramowitz, M. and Stegun, I. A., Handbook of Mathematical Functions, 10th printing, New York: Dover, 1964, pp. 79. http://www.math.sfu.ca/~cbm/aands/
We expect the arctan of 0 to be 0, and of 1 to be pi/4: >>> import mars.tensor as mt
>>> mt.arctan([0, 1]).execute() array([ 0. , 0.78539816])
>>> mt.pi/4 0.78539816339744828
Plot arctan:
>>> import matplotlib.pyplot as plt >>> x = mt.linspace(10, 10) >>> plt.plot(x.execute(), mt.arctan(x).execute()) >>> plt.axis('tight') >>> plt.show()