Re: [Matplotlib-users] PolyCollection API

[Tony S Yu <ts...@gm...>]

On Jul 27, 2010, at 2:14 PM, Mathew Yeates wrote:

> I installed matplotlib 1.0 and now I get a different error
> s=[0,0,8,8]
> ys=[0,8,8,0]
> verts=zip(xs,ys)
> poly = PolyCollection(verts)
> 
> fails at line 587 in collections because
> xy = array([0, 0]) # xy.shape = (2,)
> and line 587 says xy = np.concatenate([xy, np.zeros((1,2))])
> 
> What do I do?
> 
> -Mathew
> 


I don't really use PolyCollection, but the docstring suggests you need to put your "verts" inside of a list:
> *verts* is a sequence of ( *verts0*, *verts1*, ...) where
>     *verts_i* is a sequence of *xy* tuples of vertices, or an
>     equivalent :mod:`numpy` array of shape (*nv*, 2).
It's a bit confusing, but the first argument, "verts", is actually a sequence, of a sequence, of vertices (the repetition is intentional). For example:

square = [(0, 0), (0, 4), (4, 4), (4, 0)]
triangle = [(0, 4), (0, 7), (4, 4)]
verts = [square, triangle]

In other words, the "verts" you created in your description describes a single polygon, where as verts should be a list of polygons.

-Tony