Re: [Matplotlib-users] Polygon contains_point() different from matplotlib.nxutils.points_inside_poly?

[Benjamin R. <ben...@ou...>]

On Mon, Feb 13, 2012 at 2:59 PM, Jerzy Karczmarczuk <
jer...@un...> wrote:

>
>  reckoner:
>
>
>>
>> >>> th= array([ 4.65542641,  5.32920696,  2.20928291])
>> >>> p=patch.Polygon(array([cos(th),sin(th)]).T)
>> >>> print p.contains_point((0,0))
>> 1
>> >>> print matplotlib.nxutils.pnpoly(0,0,p.get_path().vertices)
>> 0
>>
>> Thanks!
>>
>>
>>
> I can confirm this for both the current development branch and v1.1.x.
> Strange....
>
> Ben Root
>
>   HYPOTHESIS (I have no time to check now everything..., I did my best.)
>
> If radius=None, it is converted into radius=1 in contains_point (in Patch).
> (This is the linewidth !)
> I am not sure whether it is ok, i.e. in pixels. If this value is
> considered to be relative to axes, it is enormous!
>
> p.contains_point((0,0),radius=0.01)
>
> gives 0 as it should.
>
> Jerzy Karczmarczuk
>
> P.S. I suggest anyway that reckoner submits a complete program with
> imports. What is "patch"??
>
>
>
Jerzy is right.  contains() and contains_point() both takes a radius
argument as this function is intended for use when mouse-clicking.  If no
radius is given, it uses the object's linewidth and passes it to the path's
contains_point() function with its transform.  I *suspect* that the problem
is that the transforms haven't been fully defined yet and might be
incorrectly testing this.

This needs a bit more investigation to see if this is the intended behavior
or if something needs to be fixed.

As a side note, "patch" is an imported module via "from matplotlib import
patches as patch".  Not standard among mpl devs, but not out of the
ordinary.

Ben Root