Hello list! I have a question regarding the colors of the pie diagram of matplotlib. When no colors are assigned then the pie function automatically selects some colors, like the example image I have attached. But in this case the black color covers the text. How can we avoid this?Is there an easy (perhaps?) way to exclude a color? Of course there is not problem if I specifically select the colors but I do not know how many parts exist beforehand (and I would like to assign it automatically). Thanks! Regards Grigoris
On Wed, Nov 30, 2011 at 10:34 AM, Grigoris Maravelias <
gr....@gm...> wrote:
> Hello list!
>
> I have a question regarding the colors of the pie diagram of matplotlib.
> When no colors are assigned then the pie function automatically selects
> some colors, like the example image I have attached. But in this case the
> black color covers the text. How can we avoid this?Is there an easy
> (perhaps?) way to exclude a color?
>
I don't really use pie charts, but I think it just uses the default color
cycle. This can be altered by changing the rcParams:
>>> import matplotlib.pyplot as plt
>>> plt.rcParams['axes.color_cycle'].remove('k')
The color_cycle parameter is just a python list, so I use list.remove to
remove black (which is the letter 'k' since 'b' is blue). There are other
ways of setting rcParams, as detailed in the help
files<http://matplotlib.sourceforge.net/users/customizing.html>(Note
that `rc` and `rcParams` is in both matplotlib.pyplot and the main
matplotlib package).
Best,
-Tony
Well I did tried this but it didn't work out. It actually removes the
black color from the color_cycle but the pie still prints it. Moreover I
noticed that this color_cycle has 7 colors that repeats after the first
7 so it won't do what I want. I will need to find another way to set the
colors or just avoid the pie.
Thanks though for the help!
Regards
Grigoris
On 11/30/2011 06:09 PM, Tony Yu wrote:
> On Wed, Nov 30, 2011 at 10:34 AM, Grigoris Maravelias
> <gr....@gm... <mailto:gr....@gm...>> wrote:
>
> Hello list!
>
> I have a question regarding the colors of the pie diagram of
> matplotlib. When no colors are assigned then the pie function
> automatically selects some colors, like the example image I have
> attached. But in this case the black color covers the text. How
> can we avoid this?Is there an easy (perhaps?) way to exclude a color?
>
>
> I don't really use pie charts, but I think it just uses the default
> color cycle. This can be altered by changing the rcParams:
>
> >>> import matplotlib.pyplot as plt
> >>> plt.rcParams['axes.color_cycle'].remove('k')
>
> The color_cycle parameter is just a python list, so I use list.remove
> to remove black (which is the letter 'k' since 'b' is blue). There are
> other ways of setting rcParams, as detailed in the help files
> <http://matplotlib.sourceforge.net/users/customizing.html> (Note that
> `rc` and `rcParams` is in both matplotlib.pyplot and the main
> matplotlib package).
>
> Best,
> -Tony
On Wed, Nov 30, 2011 at 6:31 PM, Grigoris Maravelias < gr....@gm...> wrote: > ** > Well I did tried this but it didn't work out. It actually removes the > black color from the color_cycle but the pie still prints it. Moreover I > noticed that this color_cycle has 7 colors that repeats after the first 7 > so it won't do what I want. I will need to find another way to set the > colors or just avoid the pie. > > I guess I should atleast read the docstring for plt.pie before giving you advice on how to use it. It looks like the default colors are hard coded into the function (instead of using the color_cycle parameter). The quickest way to create different colors is to pick them out from a colormap. For example, the following gives decent results: >>> colors = plt.cm.Set1(np.linspace(0,1,9)) >>> plt.pie(np.ones(9), colors=colors) Of course, trying to get more (visually-differentiable) colors out of the color map will be difficult. Hope that helps, -Tony
On Wednesday, November 30, 2011, Tony Yu <ts...@gm...> wrote: > > > On Wed, Nov 30, 2011 at 6:31 PM, Grigoris Maravelias < gr....@gm...> wrote: >> >> Well I did tried this but it didn't work out. It actually removes the black color from the color_cycle but the pie still prints it. Moreover I noticed that this color_cycle has 7 colors that repeats after the first 7 so it won't do what I want. I will need to find another way to set the colors or just avoid the pie. >> > > I guess I should atleast read the docstring for plt.pie before giving you advice on how to use it. It looks like the default colors are hard coded into the function (instead of using the color_cycle parameter). > > The quickest way to create different colors is to pick them out from a colormap. For example, the following gives decent results: > >>>> colors = plt.cm.Set1(np.linspace(0,1,9)) >>>> plt.pie(np.ones(9), colors=colors) > > Of course, trying to get more (visually-differentiable) colors out of the color map will be difficult. > > Hope that helps, > -Tony > > Just making a note to myself. I have bits and pieces of a property cycling mechanism (originally to cycle line styles). I am finding that cycling is very inconsistent throughout mpl, and I should probably add pie() to that list as well. As an additional note, would it be a desirable feature to be able to cycle hash styles in the case of producing b&w plots? Ben Root
On Wed, Nov 30, 2011 at 7:43 PM, Benjamin Root <ben...@ou...> wrote: > As an additional note, would it be a desirable feature to be able to cycle > hash styles in the case of producing b&w plots? > > Ben Root Ben, I think this would be quite useful. How are you thinking of implementing it? Cycling through lines = ['-', '--', '-.', etc] or through dashes = [(20,10), (5,5), (30,7), etc]? -paul