如何避免在MatPlotLib ver.2.0.2中重叠饼图标签?

时间:2017-08-18 06:18:33

标签: python matplotlib pie-chart overlap labels

关于饼图绘制的标签重叠,发布了很多问题。但是,除了将它们转换为图例之外,我无法找到自动解决方案。这个解决方案对我不起作用,因为我有很多值(大约60个),转换为图例会使情节看起来非常混乱和不清楚。所以我的问题是,如果我想在馅饼周围标记馅饼楔,那么MatPlotLib版本2.0.2的任何自动化解决方案都能使标签具有良好的间距(不重叠)? 我找到的唯一解决方案是使用 annotation() 手动完成。请参阅下面带有虚拟值的脚本。还可以用饼箭头将馅饼的楔形连接到相关的标签上吗?

我使用Python 2.7和MatPlotLib 2.0.2

谢谢,

示例1(重叠标签)

enter image description here

示例2(手动更正)

enter image description here

import pylab 
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
l = ax.pie([1,0.2, 0.3,0.1,0.4,7,50,35,5,2],#[0, 0.1, 0, 0.1,0,0.1,0,0.1,0,0.1],
            #labels=("one","two","three made up sentences","four is also ther","five becomes a sentence","six it is","seven long", "eight long sent", "nine, as bla bel mo","ten is also short"),
            labels=("","","","","","six it is","seven long", "eight long sent", "nine, as bla bel mo","ten is also short"),
            colors=("b","g","r","y", "b","g","r","y","g","black"),
            startangle =20,
            radius=1,
            frame=True,   # Plot axes frame with the chart if true.
            labeldistance = 1.1 ) #returns a list of matplotlib.patches.Wedge objects

l2 = ax.pie([1,0.2, 0.3,0.1,0.4,7,50,35,5,2],#[0, 0.1, 0, 0.1,0,0.1,0,0.1,0,0.1],
            colors=("r","g","b","w", "g","b","y","r","w","black"),
            startangle =20,
            radius=1-0.7,
            frame=True)   # Plot axes frame with the chart if true.

coor = [t.get_position() for t in l[1]]

ax.axis('equal')
plt.annotate( 'one was very short now ext', xy= (coor[0][0], coor[0][1]) )      # https://kite.com/docs/python/matplotlib.pyplot.annotate
plt.annotate( 'two long sentense',          xy= (coor[1][0], coor[1][1]) ) 
plt.annotate('three things to say' ,        xy= (coor[2][0], coor[2][1]+0.02) ) 
plt.annotate( 'four main tasks to do',      xy= (coor[3][0], coor[3][1]+0.04) ) 
plt.annotate( 'five reasons to avoid',      xy= (coor[4][0], coor[4][1]+0.06 ))   

plt.savefig('test_draft.pdf')
plt.show()

1 个答案:

答案 0 :(得分:2)

您可以尝试旋转文字。以下确定每个楔形的角度,然后相应地旋转注释文本。根据角度需要进行一些额外的调整以确定文本对齐方式,并确保文本不会出现颠倒。您可能需要进一步完善此功能。

import pylab 
import matplotlib.pyplot as plt
import math

fig, ax = plt.subplots()

labels= [
    "one",
    "two", 
    "three made up sentences", 
    "four is also there", 
    "five becomes a sentence",
    "six it is",
    "seven long", 
    "eight long sent", 
    "nine, as bla bel mo",
    "ten is also short"]

l = ax.pie([1,0.2, 0.3,0.1,0.4,7,50,35,5,2],
            labels=[''] * len(labels),
            colors=("b","g","r","y", "b","g","r","y","g","black"),
            startangle=20,
            radius=1,
            frame=True,   # Plot axes frame with the chart if true.
            labeldistance=1.1) #returns a list of matplotlib.patches.Wedge objects

l2 = ax.pie([1,0.2, 0.3,0.1,0.4,7,50,35,5,2],#[0, 0.1, 0, 0.1,0,0.1,0,0.1,0,0.1],
            colors=("r","g","b","w", "g","b","y","r","w","black"),
            startangle=20,
            radius=1-0.7,
            frame=True)   # Plot axes frame with the chart if true.

for label, t in zip(labels, l[1]):
    x, y = t.get_position()
    angle = int(math.degrees(math.atan2(y, x)))
    ha = "left"
    va = "bottom"

    if angle > 90:
        angle -= 180

    if angle < 0:
        va = "top"

    if -45 <= angle <= 0:
        ha = "right"
        va = "bottom"

    plt.annotate(label, xy=(x,y), rotation=angle, ha=ha, va=va, size=8)

ax.axis('equal')
plt.show() 

将显示为:

pie with rotated annotations