arctan(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj])

Some inconsistencies with the Dask version may exist.

Trigonometric inverse tangent, element-wise.

The inverse of tan, so that if y = tan(x) then x = arctan(y) .

Notes

arctan is a multi-valued function: for each x there are infinitely many numbers :None:None:`z` such that tan(:None:None:`z`) = x. The convention is to return the angle :None:None:`z` whose real part lies in [-pi/2, pi/2].

For real-valued 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 :None:None:`invalid` floating point error flag.

For complex-valued 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 :None:None:`atan` or tan^{-1}.

Parameters

x : array_like

out : ndarray, None, or tuple of ndarray 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 freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs.

where : array_like, optional

This condition is broadcast over the input. At locations where the condition is True, the :None:None:`out` array will be set to the ufunc result. Elsewhere, the :None:None:`out` array will retain its original value. Note that if an uninitialized :None:None:`out` array is created via the default out=None , locations within it where the condition is False will remain uninitialized.

**kwargs :

For other keyword-only arguments, see the ufunc docs <ufuncs.kwargs> .

Returns

out : ndarray or scalar

Out has the same shape as x. Its real part is in [-pi/2, pi/2] ( arctan(+/-inf) returns +/-pi/2 ). This is a scalar if x is a scalar.

This docstring was copied from numpy.arctan.

See Also

angle

Argument of complex values.

arctan2

The "four quadrant" arctan of the angle formed by (:None:None:`x`, :None:None:`y`) and the positive :None:None:`x`-axis.

Examples

We expect the arctan of 0 to be 0, and of 1 to be pi/4:

This example is valid syntax, but we were not able to check execution

>>> np.arctan([0, 1])  # doctest: +SKIP
array([ 0.        ,  0.78539816])

This example is valid syntax, but we were not able to check execution

>>> np.pi/4  # doctest: +SKIP
0.78539816339744828

Plot arctan:

This example is valid syntax, but we were not able to check execution

>>> import matplotlib.pyplot as plt  # doctest: +SKIP
... x = np.linspace(-10, 10)  # doctest: +SKIP
... plt.plot(x, np.arctan(x))  # doctest: +SKIP
... plt.axis('tight')  # doctest: +SKIP
... plt.show()  # doctest: +SKIP

See :

Back References

The following pages refer to to this document either explicitly or contain code examples using this.

dask.array.ufunc.arctan2 dask.array.ufunc.arccos dask.array.ufunc.arcsin dask.array.ufunc.arctan

Local connectivity graph

Hover to see nodes names; edges to Self not shown, Caped at 50 nodes.

Using a canvas is more power efficient and can get hundred of nodes ; but does not allow hyperlinks; , arrows or text (beyond on hover)

SVG is more flexible but power hungry; and does not scale well to 50 + nodes.

All aboves nodes referred to, (or are referred from) current nodes; Edges from Self to other have been omitted (or all nodes would be connected to the central node "self" which is not useful). Nodes are colored by the library they belong to, and scaled with the number of references pointing them

---

File: /dask/array/ufunc.py#None
type: <class 'dask.array.ufunc.ufunc'>
Commit: