[SciPy-dev] Numpy example for arctan2 perhaps wrong/misleading/confusing?

Stéfan van der Walt stefan@sun.ac...
Mon Jun 9 08:38:42 CDT 2008

Hi Samuel

2008/6/9 Samuel John <scipy@samueljohn.de>:
> Hi all,
> the page
> http://www.scipy.org/Numpy_Example_List_With_Doc#head-ad8dc60988f26f59ebe565e4af24dc95fcb8a7e9
> describes the numpy.arctan2 function and gives an example:
>> arctan2(array([0, 1]), array([1, 0]))
> However in the example there are used two arrays as arguments to
> arctan2, where it should probably be the x and y component of a single
> 2D vector. What arctan2(x,y) returns is the angle between the 2D
> vector (x,y) and the x axis. The example made me assume that it can
> compute the angle between two vectors, which it does obviously not.
> Wikipedia has a nice article on atan2. I think arctan2 works the same, or?
> http://en.wikipedia.org/wiki/Atan2
> What could be the reason of using arrays in arctan2? Could someone
> update the documentation?
> Also help(numpy.arctan2) is not very helpful, to be honest.

You're right, it is not.  Would you like to improve it?

Please register an account for yourself on our documentation wiki:


I'll then give you permission to edit docstrings.


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