Re: [matplotlib-devel] Request for feedback regarding creation of a plot-type object.

[Perry G. <pe...@st...>]

On Nov 3, 2005, at 12:55 AM, Jordan Dawe wrote:

>
>> Isn't this closely related to the idea we've tslked about a number of
>> times (mostly off list) to supplant the colormap infrastructure with a
>> "DiscreteColormap" or something along those lines, which mapped data
>> to a set of discrete colors, using nearest neighbor or what have
>> you.  Then you would have the best of both worlds: your favorite
>> colors and consistency with the mpl colorbar/colormapping API.  Would
>> this work?
>>
> I don't quite understand the idea here, but the colorbar mapping is 
> really only part of this.  If you make classes for each plot type, you 
> could do things like make legend() a call to the PlotClass.Legend() 
> method, and each plot could make it's own kind of legend.
>
> I know this is a large architecture change, but it could be 
> implimented incrimentally and I think it would give a lot of benefits 
> in regards to what you could do with customizing different plot 
> behaviours.  But, as I said before, I don't really have nearly the 
> grasp of the matplotlib codebase that the devs do.  It doesn't look 
> too difficult to me, but there are probably issues I am not aware of.  
> Is there any reason each plot type shouldn't have it's own class?
>
I get the feeling that two different ideas are being discussed here. A 
discrete color map still would require someone to define a custom one 
if they have a favorite set of colors they want to use for each contour 
level. That involves some level of inconvenience. I gather from what 
Jordan is saying is that he wants to be able to automatically construct 
a colorbar from the colors assigned to each contour level without 
having to construct a colormap in the first place. That is, after the 
contour is done with its specific color/level assignments, then a 
request for a colorbar would show a linear relationship between data 
levels and the discrete colors chosen. Do I understand correctly?

Perry