在Matplotlib中,我正在尝试制作一个带有彩色“标记”的图例,就像这样:
这是使用scatter
函数创建的,但不适合我的情节。我想“从头开始”制作一个没有相关数据的图例。颜色很重要,因此应该是每个标记的属性。
我试过了
import matplotlib.markers as mmark
list_mak = [mmark.MarkerStyle('.'),mmark.MarkerStyle(','),mmark.MarkerStyle('o')]
list_lab = ['Marker 1','Marker 2','Marker 3']
plt.legend(list_mak,list_lab)
但是:
1) MarkerStyle
类不支持颜色信息
2)我得到警告:
UserWarning: Legend does not support <matplotlib.markers.MarkerStyle object at 0x7fca640c44d0> instances.
A proxy artist may be used instead.
但是我如何定义一个基于标记的代理艺术家呢?
感谢您的帮助!
发布于 2017-11-20 13:17:23
按照legend guide中给出的示例,可以使用Line2D
对象而不是marker
对象。
与指南中给出的示例的唯一不同之处在于,您希望设置linestyle='None'
import matplotlib.lines as mlines
import matplotlib.pyplot as plt
blue_star = mlines.Line2D([], [], color='blue', marker='*', linestyle='None',
markersize=10, label='Blue stars')
red_square = mlines.Line2D([], [], color='red', marker='s', linestyle='None',
markersize=10, label='Red squares')
purple_triangle = mlines.Line2D([], [], color='purple', marker='^', linestyle='None',
markersize=10, label='Purple triangles')
plt.legend(handles=[blue_star, red_square, purple_triangle])
plt.show()
发布于 2017-11-20 15:24:41
您可以将HandlerBase
子类化,以从(color, marker)
的元组创建处理程序。
import matplotlib.pyplot as plt
from matplotlib.legend_handler import HandlerBase
list_color = ["c", "gold", "crimson"]
list_mak = ["d","s","o"]
list_lab = ['Marker 1','Marker 2','Marker 3']
ax = plt.gca()
class MarkerHandler(HandlerBase):
def create_artists(self, legend, tup,xdescent, ydescent,
width, height, fontsize,trans):
return [plt.Line2D([width/2], [height/2.],ls="",
marker=tup[1],color=tup[0], transform=trans)]
ax.legend(list(zip(list_color,list_mak)), list_lab,
handler_map={tuple:MarkerHandler()})
plt.show()
https://stackoverflow.com/questions/47391702
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