matplotlib-devel Mailing List for matplotlib

Hi John and Jae-Joon,
While it hardly solves *all* of the issues I've been having it does work 
for this problem:) Thanks a ton. As for committing it to the repository 
I'd be honored if Jae Joon agrees. Should I clean it up and remove the 
debugging prints?
Elan
----
"If stupidity got us into this mess, why can't it get us out?"
 	- Will Rogers
On Sat, 9 May 2009, John Hunter wrote:
> On Sat, May 9, 2009 at 12:08 PM, Jae-Joon Lee <lee...@gm...> wrote:
>> Here is a slightly modified version of your script which works for me.
>>
>> I don't think this is the bug in mpl. Note that the ax.bbox does
>> change if the canvas size change. In your original script, the
>> copy_from_bbox is called before frame.Show() and this seems to cause a
>> mismatching bbox.
>>
>> My modified example is also not perfect. A new background image needs
>> to be saved whenever ax.bbox changes (e.g. when resizing canvas).
>
> probably best way to do this is to connect to the draw_event, and
> update the background on the draw_event. I've updated the example and
> attached it -- do you mind if I commit it to the mpl examples dir (and
> does this solve all the issues you are having)?
>
> JDH
>

John Hunter wrote:
> On Sat, May 9, 2009 at 9:32 AM, Freddie Witherden <fr...@wi...> wrote:
>> Hi all,
>>
>> As some of you probably know I am working on the GSoC project to
>> externalise the Mathtex engine from Matplotlib. Today I have been
>> toying around with the renderer using various backends.
>>
>> One of the interesting things that I discovered was that the Cairo
>> backend was making use of subpixel rendering. (Or 'ClearType' as
>> Microsoft call it.) This is not surprising -- by default Cairo will
>> respect a users fontconfig settings when rendering text. Since I have
>> subpixel rendering enabled all text rendered by Cairo is subpixel
>> rendered.
>>
>> While this is fantastic for on screen text -- being significantly more
>> pleasing to look at that the text produced by the AGG backend -- it is
>> unsuitable for print. Now it is not too difficult to disable this,
>> Cairo has an API call: cairo_font_options_set_antialias to deal with
>> this.
>>
>> While I could write a quick patch to always disable subpixel rendering
>> it would be something off a loss to those who either view their graphs
>> onscreen or export them for the web -- where using subpixel rendering
>> is now surprisingly common.
>>
>> Is it worth looking into adding subpixel rendering as a configuration
>> option?
> 
> The matplotlib.lines.Line2D objects has an antialiased property -- we
> could add the same property to matplotlib.text.Text to turn on/off
> subpixel rendering (which could also be supported as an rc param)
I haven't poked around, so this may be a stupid question, but: for 
cairo, can subpixel rendering simply be left on for screen display and 
automatically turned off when writing to a file via savefig? If this 
can be done, it seems like a better solution than requiring to the user 
to turn the parameter on and off manually, depending on whether show() 
or savefig() is being called.
Eric
> 
> JDH

On Sat, May 9, 2009 at 9:32 AM, Freddie Witherden <fr...@wi...> wrote:
> Hi all,
>
> As some of you probably know I am working on the GSoC project to
> externalise the Mathtex engine from Matplotlib. Today I have been
> toying around with the renderer using various backends.
>
> One of the interesting things that I discovered was that the Cairo
> backend was making use of subpixel rendering. (Or 'ClearType' as
> Microsoft call it.) This is not surprising -- by default Cairo will
> respect a users fontconfig settings when rendering text. Since I have
> subpixel rendering enabled all text rendered by Cairo is subpixel
> rendered.
>
> While this is fantastic for on screen text -- being significantly more
> pleasing to look at that the text produced by the AGG backend -- it is
> unsuitable for print. Now it is not too difficult to disable this,
> Cairo has an API call: cairo_font_options_set_antialias to deal with
> this.
>
> While I could write a quick patch to always disable subpixel rendering
> it would be something off a loss to those who either view their graphs
> onscreen or export them for the web -- where using subpixel rendering
> is now surprisingly common.
>
> Is it worth looking into adding subpixel rendering as a configuration
> option?
The matplotlib.lines.Line2D objects has an antialiased property -- we
could add the same property to matplotlib.text.Text to turn on/off
subpixel rendering (which could also be supported as an rc param)
JDH

On Sat, May 9, 2009 at 12:08 PM, Jae-Joon Lee <lee...@gm...> wrote:
> Here is a slightly modified version of your script which works for me.
>
> I don't think this is the bug in mpl. Note that the ax.bbox does
> change if the canvas size change. In your original script, the
> copy_from_bbox is called before frame.Show() and this seems to cause a
> mismatching bbox.
>
> My modified example is also not perfect. A new background image needs
> to be saved whenever ax.bbox changes (e.g. when resizing canvas).
probably best way to do this is to connect to the draw_event, and
update the background on the draw_event. I've updated the example and
attached it -- do you mind if I commit it to the mpl examples dir (and
does this solve all the issues you are having)?
JDH

Here is a slightly modified version of your script which works for me.
I don't think this is the bug in mpl. Note that the ax.bbox does
change if the canvas size change. In your original script, the
copy_from_bbox is called before frame.Show() and this seems to cause a
mismatching bbox.
My modified example is also not perfect. A new background image needs
to be saved whenever ax.bbox changes (e.g. when resizing canvas).
-JJ
On Fri, May 8, 2009 at 5:02 PM, Elan Pavlov <ep...@gm...> wrote:
> Hi,
> Restore_region does not appear to work when embedding mpl into
> wxpython. Attached is a simple modification of the cookbook animation
> (http://www.scipy.org/Cookbook/Matplotlib/Animations) to illustrate
> this problem. I modified the example so it is updated on mouse
> movements (followed by idle time) so that the problem is more visual.
> There is also a flag to add one second timeouts between commands in
> the update method. When looking at the slowed animation it is clear
> that the background is never restored.
> Michiel Hoon thinks that the problem is due to the fact that
> restore_region is not implemented within the event loop and that the
> proper solution requires discussion:)
>
> Elan
> ---
> Of joys departed, not to return, how painful the remembrance.
> - Robert Blair
>
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>

Hi all,
As some of you probably know I am working on the GSoC project to 
externalise the Mathtex engine from Matplotlib. Today I have been 
toying around with the renderer using various backends.
One of the interesting things that I discovered was that the Cairo 
backend was making use of subpixel rendering. (Or 'ClearType' as 
Microsoft call it.) This is not surprising -- by default Cairo will 
respect a users fontconfig settings when rendering text. Since I have 
subpixel rendering enabled all text rendered by Cairo is subpixel 
rendered.
While this is fantastic for on screen text -- being significantly more 
pleasing to look at that the text produced by the AGG backend -- it is 
unsuitable for print. Now it is not too difficult to disable this, 
Cairo has an API call: cairo_font_options_set_antialias to deal with 
this.
While I could write a quick patch to always disable subpixel rendering 
it would be something off a loss to those who either view their graphs 
onscreen or export them for the web -- where using subpixel rendering 
is now surprisingly common.
Is it worth looking into adding subpixel rendering as a configuration 
option?
Regards, Freddie.

I'm running into the following error with the wx backend
> >>> import wx
> >>> import matplotlib.backends.backend_wxagg
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> File "/Users/Tony/python/matplotlib/trunk/matplotlib/lib/ 
> matplotlib/backends/backend_wxagg.py", line 23, in <module>
> import backend_wx # already uses wxversion.ensureMinimal('2.8')
> File "/Users/Tony/python/matplotlib/trunk/matplotlib/lib/ 
> matplotlib/backends/backend_wx.py", line 120, in <module>
> except wxversion.AlreadyImportedError:
> AttributeError: 'module' object has no attribute 
> 'AlreadyImportedError'
This problem seems to be related to additions made here:
http://www.nabble.com/Selecting-WX2.8-in-examples-td22380586.html
The problem is that my version of wxversion raises 'VersionError' 
instead of 'AlreadyImportedError'.
I'm running wxPython 2.8.4.0 while people in the above thread seem to 
be using at least 2.8.7.1. Do I need to upgrade, or is this a bug?
Thanks,
-Tony