Changing line properties in matplotlib pie chart

Question

I'm trying to make the lines on my matplotlib pie chart much lighter. Because I have so many slices, the lines are way too thick, as shown here:

enter image description here

I read this example which suggests using rcparam like this:

matplotlib.rcParams['text.color'] = 'r'
matplotlib.rcParams['lines.linewidth'] = 2

but although I can change the text color, it doesn't change the width of the lines between the pie slices. I believe that's because the slices aren't governed by line objects but by wedge objects. So is there a way to set the wedge border style and color?

Thanks a lot, Alex

behzad.nouri · Accepted Answer · 2016-05-22T12:59:21.797

17

try this:

ax = plt.subplot(111) 
wedges, texts = ax.pie(np.abs(np.random.randn(5)))

for w in wedges:
    w.set_linewidth(2)
    w.set_edgecolor('cyan')

pie

Additionally, if you only have an axes object and don't have direct access to the pie's wedges you can retrieve the wedges from ax.patches:

wedges = [patch for patch in ax.patches if isinstance(patch, matplotlib.patches.Wedge)]

edited May 22 '16 at 12:59

answered Dec 12 '13 at 19:01

behzad.nouri

74,723
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You can probably also pass in `linewidth` when you call `pie`. – tacaswell Dec 12 '13 at 19:19
@tcaswell just tried that on matplotlib `1.3.1`, did not work – behzad.nouri Dec 12 '13 at 19:24
1

Yeah, that is odd/not right. Most of the plot signatures have a `**kwarg`, but `pie` does not. I may do something about this if I have time today. – tacaswell Dec 12 '13 at 19:34
Perfect, thanks a lot. Can confirm, pie does not have a regular linewidth/color option, so have to jump through these hoops. – Alex S Dec 12 '13 at 19:54
@tcaswell Please do! I'd love to pass linewidth in to pie… – aclark Mar 13 '14 at 23:30
@aclark Can you create an issue on github about this? Otherwise I will forget again ;) – tacaswell Mar 14 '14 at 14:08
@tcaswell i added the [issue](https://github.com/matplotlib/matplotlib/issues/2899) on github – behzad.nouri Mar 14 '14 at 14:15

score 6 · Answer 2 · answered Apr 03 '14 at 15:13

6

Im coming late to this party, but just found that, for pie charts, instead of using:

plt.rcParams['lines.linewidth'] = 2

you can use:

plt.rcParams['patch.linewidth'] = 0

Also, to change the pie chart line color use this:

plt.rcParams['patch.edgecolor'] = 'white'

instead of:

plt.rcParams['line.color'] = 'white'

answered Apr 03 '14 at 15:13

Manuel G

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Much more intuitive and easier than the above for basic needs, thanks. – Konrad Nov 11 '16 at 10:52

Changing line properties in matplotlib pie chart

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