On 11/10/2010 10:41 AM, Benjamin Root wrote:
On Tue, Nov 9, 2010 at 8:44 PM, Jae-Joon Lee <lee.j.j...@gmail.com
<mailto:lee.j.j...@gmail.com>> wrote:
On Wed, Nov 10, 2010 at 1:01 AM, Jason Grout
<jason-s...@creativetrax.com <mailto:jason-s...@creativetrax.com>>
wrote:
> Is the tip of the arrow (after the miter join) supposed to hit
(1,1), or is
> the center of the line supposed to hit (1,1)? Or maybe the tip
of the
> joinstyle='round' arrow (the default) is supposed to hit (1,1)?
>
The tip of the arrow is meant to hit (1,1), which is done by the
underlying arrow class adjusting the end point of the path during the
drawing time. This only happens for arrowstyle "->" and etc.
However, there was an incorrect arithmetic which I think is fixed now.
The patch is attached (it also fixes dpi-related issues).
I'm not sure it would be better if this could be optionally turned
off. Any suggestion?
Let me know of any (persisting or other) issues.
FYI, path is shortened by small amount by default. This is controlled
by *shrink* parameter (shrinkA and shrinkB shortens the line begin and
the line end respectively.)
aa = ax.annotate('', (1,1), (0,0),
arrowprops=dict(arrowstyle="-|>",
fc="k", ec="k",lw=50,
shrinkB=0,
path_effects=[Stroke(joinstyle='miter')]
)
Also, I noticed that the arrow head is not correctly filled when
path_effects are in use. This is now fixed.
Regards,
-JJ
I just seem to break things...
I am not 100% sure if the tip is placed correctly, but it does appear
much better than before. I now see a tiny bit of the red line
southwest of the vertex. Before, the issue was that the arrow tip was
northeast of the vertex. In addition, I found that I was still able
to produce the distortion after zooming in sufficiently (it took a few
extra zooms to make it happen).
I then did one more zoom, and then tried resizing the window, and I
think I broke the Agg renderer. Two exceptions were raised. First,
an overflow error occurred while rendering the path (complexity
exceeded). Then, an "SystemError: error return without exception set"
exception was raised from the same spot. I am wondering if zooming
into the arrow distortion and/or resizing the figure window triggered
the complexity issue, and then the error handling routines weren't
properly handling the raised exception. Here was my traceback:
The reason for the rendering complexity problem is that the arrow
extends way, way, way off the edge of the image such that the values
overflow (in pixel units) -- Agg uses 24.8 fixed-point arithmetic
internally. The exception throwing itself in this case was broken
(since fixed). Once the exception is thrown, it will always need to be
thrown in subsequent calls into Agg, since there doesn't seem to be a
clean way to recover from the exception. (There might be, but it gets
down into a much hairier patch to Agg than I've been able to work through).
matplotlib currently supports clipping paths to the bounds of the image
which prevents these huge values from getting passed to the Agg layer
and blowing it up. Unfortunately, this algorithm only works on
un-filled paths. Arrows are implemented as filled shapes, so this
clipping functionality is turned off for them. The solution seems to be
to implement a more sophisticated algorithm that would clip the path to
the rectangle correctly. Certainly such algorithms exist.
Mike
Traceback (most recent call last):
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/backends/backend_gtk.py",
line 394, in expose_event
self._render_figure(self._pixmap, w, h)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/backends/backend_gtkagg.py",
line 75, in _render_figure
FigureCanvasAgg.draw(self)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/backends/backend_agg.py",
line 394, in draw
self.figure.draw(self.renderer)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/figure.py",
line 874, in draw
func(*args)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/axes.py",
line 1954, in draw
a.draw(renderer)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/text.py",
line 1986, in draw
self.arrow_patch.draw(renderer)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/patches.py",
line 3930, in draw
path_effect.draw_path(renderer, gc, p, affine, None)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/patheffects.py",
line 121, in draw_path
renderer.draw_path(gc0, tpath, affine, None)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/backends/backend_agg.py",
line 117, in draw_path
self._renderer.draw_path(gc, path, transform, rgbFace)
OverflowError: Agg rendering complexity exceeded. Consider
downsampling or decimating your data.
Traceback (most recent call last):
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/backends/backend_gtk.py",
line 394, in expose_event
self._render_figure(self._pixmap, w, h)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/backends/backend_gtkagg.py",
line 75, in _render_figure
FigureCanvasAgg.draw(self)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/backends/backend_agg.py",
line 394, in draw
self.figure.draw(self.renderer)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/figure.py",
line 814, in draw
if self.frameon: self.patch.draw(renderer)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/patches.py",
line 411, in draw
renderer.draw_path(gc, tpath, affine, rgbFace)
File
"/home/bvr/Programs/matplotlib/matplotlib/lib/matplotlib/backends/backend_agg.py",
line 117, in draw_path
self._renderer.draw_path(gc, path, transform, rgbFace)
SystemError: error return without exception set
------------------------------------------------------------------------------
The Next 800 Companies to Lead America's Growth: New Video Whitepaper
David G. Thomson, author of the best-selling book "Blueprint to a
Billion" shares his insights and actions to help propel your
business during the next growth cycle. Listen Now!
http://p.sf.net/sfu/SAP-dev2dev
_______________________________________________
Matplotlib-users mailing list
Matplotlib-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-users
------------------------------------------------------------------------------
The Next 800 Companies to Lead America's Growth: New Video Whitepaper
David G. Thomson, author of the best-selling book "Blueprint to a
Billion" shares his insights and actions to help propel your
business during the next growth cycle. Listen Now!
http://p.sf.net/sfu/SAP-dev2dev
_______________________________________________
Matplotlib-users mailing list
Matplotlib-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-users
