arctan(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj])
The inverse of tan, so that if y = tan(x)
then x = arctan(y)
.
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}.
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.
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.
For other keyword-only arguments, see the ufunc docs <ufuncs.kwargs>
.
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.
Trigonometric inverse tangent, element-wise.
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.
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]) array([ 0. , 0.78539816])This example is valid syntax, but we were not able to check execution
>>> np.pi/4 0.78539816339744828
Plot arctan:
This example is valid syntax, but we were not able to check execution>>> import matplotlib.pyplot as pltSee :
... x = np.linspace(-10, 10)
... plt.plot(x, np.arctan(x))
... plt.axis('tight')
... plt.show()
The following pages refer to to this document either explicitly or contain code examples using this.
numpy.ma.core.arccos
numpy.ma.core.arcsin
numpy.ma.core.arctan2
numpy.ma.core.arctan
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