matplotlib:使图例键变为正方形 [英] matplotlib: make legend keys square

问题描述

我正在使用matplotlib，例如在制作条形图时，我想将图例中的键更改为正方形而不是矩形.有没有办法指定这个?

I am working with matplotlib and would like to change the keys in my legends to be squares instead of rectangles when I make, for example, bar plots. Is there a way to specify this?

我现在拥有的:

我想要什么:

谢谢！

推荐答案

您可以定义自己的图例键.

You can define your own legend keys.

答案中的条形图是使用 matplotlib条形图演示创建的.(我已经删除了错误栏).matplotlib 图例指南 解释了如何定义类用椭圆代替图例键.我已经修改了该类以使用正方形(通过使用矩形补丁).

The bar plot in my answer is created using the matplotlib barchart demo. (I have removed the error bars). The matplotlib legend guide explains how to define a class to replace legend keys with ellipses. I have modified that class to use squares (by using rectangle patches).

import numpy as np
from matplotlib.legend_handler import HandlerPatch
import matplotlib.pyplot as plt
import matplotlib.patches as mpatches

# Define square (rectangular) patches
# that can be used as legend keys
# (this code is based on the legend guide example)

class HandlerSquare(HandlerPatch):
    def create_artists(self, legend, orig_handle,
                       xdescent, ydescent, width, height, fontsize, trans):
        center = xdescent + 0.5 * (width - height), ydescent
        p = mpatches.Rectangle(xy=center, width=height,
                               height=height, angle=0.0)
        self.update_prop(p, orig_handle, legend)
        p.set_transform(trans)
        return [p]      

# this example is the matplotlib barchart example:

N = 5
menMeans = (20, 35, 30, 35, 27)

ind = np.arange(N)  # the x locations for the groups
width = 0.35       # the width of the bars

fig, ax = plt.subplots()
rects1 = ax.bar(ind, menMeans, width, color='r')

womenMeans = (25, 32, 34, 20, 25)
rects2 = ax.bar(ind+width, womenMeans, width, color='y')

# add some text for labels, title and axes ticks
ax.set_ylabel('Scores')
ax.set_title('Scores by group and gender')
ax.set_xticks(ind+width)
ax.set_xticklabels( ('G1', 'G2', 'G3', 'G4', 'G5') )

# append the new patches to the legend-call:

ax.legend( (rects1[0], rects2[0]), ('Men', 'Women'), 
           handler_map={rects1[0]: HandlerSquare(), rects2[0]: HandlerSquare()})

plt.show()

已经定义了类HandlerSquare ，现在可以将其应用于每个图例条目，作为 ax.legend 调用的第三个参数.注意语法:

Having defined the class HandlerSquare, one can now apply this to each legend entry as a third argument to the ax.legend call. Note the syntax:

handler_map={rects1[0]: HandlerSquare(), rects2[0]: HandlerSquare()}

handler_map 必须是字典.

这将为您提供此情节:

这篇关于matplotlib:使图例键变为正方形的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！