matplotlib-devel Mailing List for matplotlib (Page 2)

On Sun, Apr 5, 2015 at 12:46 AM, Eric Firing <ef...@ha...> wrote:
> On 2015年04月04日 9:20 PM, Nathaniel Smith wrote:
>
>> While it's taking longer than hoped, just to reassure you that this
>> isn't total vaporware, here's a screenshot from the colormap designer
>> that Stéfan van der Walt and I have been working on... still needs
>> fine-tuning (which at this point probably won't happen until after I
>> get back from PyCon), but we like what we're seeing so far :-)
>>
>> The colormap shown has, by construction, perfect lightness linearity
>> and perfect perceptual uniformity, according to the better-than-CIELAB
>> model used by the viscm tool I linked upthread.
>>
>
> Thanks for the update, and the progress. The example colormap looks
> promising as a viable alternative. It appears to have good contrast. How
> well does this type of map work with the colorblindness filters?
Blue/yellow contrast is preserved with the common types of
colorblindness, so it should become a smooth ramp of blue ->
(reddish/greyish, depending on details/severity of color deficiency)
-> yellow. And the luminance remains linear. So it's definitely not a
disaster.
Beyond that I'm not entirely sure how to numerically quantify
perceptual uniformity for colorblind users -- we could use the
sRGB->sRGB formulas for simulating colorblindness for non-colorblind
viewers and then use the regular non-colorblind uniformity estimates,
but I have no idea how accurate that would be... my guess though is
that the way that colormaps is designed ATM it will have somewhat
faster hue shifts in the lower (blue) region than the upper (yellow)
region, and fastest in the middle, though this effect shouldn't be
huge (and to some extent is inevitable with any map that's both
colorful and perceptually uniform for non-colorblind users). Thinking
through these details is one of the things I had in mind when I
mentioned "fine tuning" above though :-).
We'd welcome any feedback from readers with non-simulated color deficiency!
-n
-- 
Nathaniel J. Smith -- http://vorpus.org

<3 <3 <3 Love the prototype colormap!!!

On 2015年04月04日 9:20 PM, Nathaniel Smith wrote:
> While it's taking longer than hoped, just to reassure you that this
> isn't total vaporware, here's a screenshot from the colormap designer
> that Stéfan van der Walt and I have been working on... still needs
> fine-tuning (which at this point probably won't happen until after I
> get back from PyCon), but we like what we're seeing so far :-)
>
> The colormap shown has, by construction, perfect lightness linearity
> and perfect perceptual uniformity, according to the better-than-CIELAB
> model used by the viscm tool I linked upthread.
>
Thanks for the update, and the progress. The example colormap looks 
promising as a viable alternative. It appears to have good contrast. 
How well does this type of map work with the colorblindness filters?
Eric

On Mon, Feb 23, 2015 at 10:46 AM, Eric Firing <ef...@ha...> wrote:
> On 2015年02月18日 2:39 PM, Nathaniel Smith wrote:
>>
>> On Feb 16, 2015 3:39 PM, "Eric Firing" <ef...@ha...> wrote:
>>>
>>>
>>> On 2015年02月16日 1:29 PM, Michael Waskom wrote:
>>>
>>>> Nathaniel's January 9 message in that thread (can't figure out how to
>>>> link to it in the archives) had a suggestion that I thought was very
>>>> promising, to do something similar to Parula but rotate around the hue
>>>> circle the other direction so that the hues would go blue - purple - red
>>>> - yellow. I don't think we've seen an example of exactly what it would
>>>> look like, but I reckon it would be similar to the middle colormap here
>>>>
>>>> http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png
>>>> (from the elegant figures block series linked above), which I've always
>>>> found quite attractive.
>>>
>>>
>>> Certainly it can be considered--but we have to have a real
>>> implementation.
>>
>>
>> While I hate to promise vaporware, I actually was planning to have a
>> go at implementing such a colormap in the next few weeks, based on
>> optimizing the same set of parameters that viscm visualizes... FWIW.
>
>
> It might be worth quite a bit--and the sooner, the better.
While it's taking longer than hoped, just to reassure you that this
isn't total vaporware, here's a screenshot from the colormap designer
that Stéfan van der Walt and I have been working on... still needs
fine-tuning (which at this point probably won't happen until after I
get back from PyCon), but we like what we're seeing so far :-)
The colormap shown has, by construction, perfect lightness linearity
and perfect perceptual uniformity, according to the better-than-CIELAB
model used by the viscm tool I linked upthread.
-- 
Nathaniel J. Smith -- http://vorpus.org

Okay, just about finished WebAgg, but it has raised an interesting 
question about layout...
I started working to standardise using the way we do it on ``Gtk3``, 
i.e. using a pure vertical layout, adding elements from either the top 
or the bottom of the container and setting widgets (i.e. the canvas) as 
expandable. In my original version of this MEP I used a boolean to 
specify whether to add to the beginning or the end of the window's 
layout. ``Tk`` gave me the idea to extend past this and use string 
argument of 'top' or 'bottom', no real difference but just to keep it 
flexible for the future.
However now I rethink that strategy having converted Qt and now on 
WebAgg, perhaps we should conform around a Grid layout, by that I mean 
we have the following:
 North
----------------------------
 | |
E | | W
a | Centre | e
s | | s
t | | t
 | |
---------------------------
 South
For now we will just use Centre and South (with the canvas in Centre; 
and Toolbar/statusbar in South), but it also leaves it open for the 
future. If I recode it like this, I would make each 5 positions a box, 
with the compass points adding elements from the outside inwards which 
keeps the pattern explained above.
What do people think? I don't feel 100% comfortable for limiting 
ourselves to just one layout, but I can persuade myself that we have to 
decide on something and atm we only have a really adhoc system, so 
definitely an improvement, and should anything happen in the future to 
make us change our mind we can the workaround of using centre as our new 
starting point, or wait for a major release.
Looking forward to getting some feedback on this.