Re: [Matplotlib-users] trouble with Arrow

[Alan G I. <ala...@gm...>]

On 2/2/2014 11:13 PM, Alan G Isaac wrote:
> A follow-on question: the `arrow` method of an axes
> has `length_includes_head` default to False.  Why?
> This seems very unfriendly behavior for an "arrow".
> It also conflicts with the behavior of an `Arrow`.

One more follow-on question:
the documented behavior of head_width and head_length is:
http://matplotlib.org/api/axes_api.html

head_width: float or None (default: 3*width)   total width of the full arrow head
head_length: float or None (default: 1.5 * head_width)   length of arrow head

But I believe that does not match the behavior I am seeing.  E.g., the following
produces two completely different arrow heads.

fig, ax = plt.subplots(1,1)
ax.set_aspect('equal')
w=0.01
ax.arrow(0,0,1,1, width=w,head_width=3*w,head_length=1.5*3*w, facecolor='red',edgecolor=None,length_includes_head=True)
ax.arrow(0,1,1,-1, width=w, facecolor='k',edgecolor='red',length_includes_head=True)

Am I missing something?

Also, despite setting `edgecolor=None`, the edge is still stroked.

Alan Isaac