matplotlib-devel Mailing List for matplotlib

Manuel Metz wrote:
> John Hunter wrote:
> 
>> On Thu, Apr 3, 2008 at 8:40 AM, Manuel Metz <mm...@as...> wrote:
>> 
>>> Hi,
>>>
>>> in matplotlib 0.91 there was a function draw_point for the backends.
>>> This seems to be gone (except for backend_agg2.py and backend_emf.py
>>> !?). I guess it wasn't used very often; instead I see that there is now
>>> a function draw_point in lines.py. Is it possible to re-add this
>>> functionality to the backends ??? What I would need is a function that
>>> draws a single pixel to a device.
>>> 
>> The markerstyle for drawing a pixel is ',' and it is supported across
>> backends AFAIK
>> 
>
> Hi John,
> thank - that's done via the draw_point in lines.py, right? Now, as far 
> as I can see this function "emulates" to draw one pixel by drawing a 
> line of length 1 pixel. I was just wondering whether its worth to have a 
> draw_point method for (pixel-based) backends (png) that have an 
> intrinsic command to draw one pixel which might be more efficient.
> 
In Agg at least, it won't be much more efficient -- the marker is drawn 
only once and then blitted multiple times. There's some overhead for 
the blitting loop, for sure, but not much -- probably not enough to 
warrant complicating the code. But, I say that without any experiments, 
so I'm happy to be proven wrong.
> But if it's done with lines for all the backends, this means that 
> draw_point() can be removed from the two files backend_agg2.py and 
> backend_emf.py !?
> 
Both of those backends are deprecated anyway -- probably best to just 
remove the backends altogether... ;)
Mike
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

John Hunter wrote:
> On Thu, Apr 3, 2008 at 8:40 AM, Manuel Metz <mm...@as...> wrote:
>> Hi,
>>
>> in matplotlib 0.91 there was a function draw_point for the backends.
>> This seems to be gone (except for backend_agg2.py and backend_emf.py
>> !?). I guess it wasn't used very often; instead I see that there is now
>> a function draw_point in lines.py. Is it possible to re-add this
>> functionality to the backends ??? What I would need is a function that
>> draws a single pixel to a device.
> 
> The markerstyle for drawing a pixel is ',' and it is supported across
> backends AFAIK
Hi John,
thank - that's done via the draw_point in lines.py, right? Now, as far 
as I can see this function "emulates" to draw one pixel by drawing a 
line of length 1 pixel. I was just wondering whether its worth to have a 
draw_point method for (pixel-based) backends (png) that have an 
intrinsic command to draw one pixel which might be more efficient.
But if it's done with lines for all the backends, this means that 
draw_point() can be removed from the two files backend_agg2.py and 
backend_emf.py !?
Manuel