matplotlib自定义图例中类别的子标题

Question

我有一个看起来像这样的数字：

我想制作一个看起来像这样的传奇：

我该怎么做？

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更新：

请注意，此图例的框架带有edgecolor：有效的答案将包含此内容。图例也应嵌入轴中。

使用ax.legend()可能无法实现我想要的图例。一个很好的答案将展示如何使用补丁和文本手动构建我想要的图例（完全如图所示），或任何有意义的matplotlib方法。

Answer 1

D和A行的单独标题：

from matplotlib.pyplot import *
ds = [1,2,3]
dc = [1.1, 1.9, 3.2]
asim = [1.5, 2.2, 3.1]
ac = [1.6, 2.15, 3.1]

categories = ['simulated', 'calculated']

p1, = plot(ds, 'ko', label='D simulated')
p2, = plot(dc, 'k:', label='D calculated')
p3, = plot(asim, 'b+', label='A simulated')
p4, = plot(ac, 'b-', label='A calculated')
p5, = plot([0], marker='None',
           linestyle='None', label='dummy-tophead')
p7, = plot([0],  marker='None',
           linestyle='None', label='dummy-empty')

leg3 = legend([p5, p1, p2, p5, p3, p4],
              [r'$D_{etc}$'] + categories + [r'$A_{etc}$'] + categories,
              loc=2, ncol=2) # Two columns, vertical group labels

leg4 = legend([p5, p7, p5, p7, p1, p2, p3, p4],
              [r'$D_{etc}$', '', r'$A_{etc}$', ''] + categories + categories,
              loc=4, ncol=2) # Two columns, horizontal group labels

gca().add_artist(leg3)

#If there isn't a big empty spot on the plot, two legends:
#leg1 = legend([p1, p2], categories, title='D_etc', loc=0)
#leg2 = legend([p3, p4], categories, title='A_etc', loc=4)
#gca().add_artist(leg2) 

show()