Matplotlib PatchCollection 到图例

Question

目前，我正在尝试通过使用 PatchCollections 创建代理艺术家 (?) 补丁，然后按照 http://matplotlib.org/users/legend_guide.html 制作自定义处理程序来制作自己的自定义图例处理程序。

但是，我在尝试将其应用到图例中时遇到了障碍。图例的参数包含补丁，但不包含补丁集合。

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.mlab as mlab
import matplotlib.patches as mpatches
from matplotlib.path import Path
from matplotlib.collections import PatchCollection

fig = plt.figure()
ax = fig.add_subplot(111)

verts1 = [(0.,0.),(0.,1.),(1.,1.),(0.51,0.51),(0.,0.),(0.,0.),]
codes1 = [Path.MOVETO,Path.LINETO,Path.LINETO,Path.LINETO,Path.MOVETO,Path.CLOSEPOLY,]
path1 = Path(verts1,codes1)
patch1 = mpatches.PathPatch(path1,ls='dashed',ec='red',facecolor="none")


verts2 = [(0.49,0.49),(0.,0.),(1.,0.),(1.,1.),(0.5,0.5),(0.,0.),]
codes2 = [Path.MOVETO,Path.LINETO,Path.LINETO,Path.LINETO,Path.MOVETO,Path.CLOSEPOLY,]
path2 = Path(verts2,codes2)
patch2 = mpatches.PathPatch(path2,ls='solid',edgecolor='red', facecolor="none")

patch = PatchCollection([patch1,patch2],match_original=True)

ax.set_xlim(-2,2)
ax.set_ylim(-2,2)

ax.add_collection(patch)

以上是可视化处理程序的代码。基本上是一个矩形，上三角为虚线，下三角为实线

使用，

plt.legend([patch],["hellocello"],loc='upper right')

重新创建错误。有解决办法吗？

Answer 1

从section 中的示例看来，您需要定义一个对象并根据句柄大小表示所有坐标，

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.mlab as mlab
import matplotlib.patches as mpatches
from matplotlib.path import Path
from matplotlib.collections import PatchCollection

class AnyObject(object):
    pass

class AnyObjectHandler(object):
    def legend_artist(self, legend, orig_handle, fontsize, handlebox):
        x0, y0 = handlebox.xdescent, handlebox.ydescent
        width, height = handlebox.width, handlebox.height
        hw = 0.5*width; hh = 0.5*height
        verts1 = [(x0,y0),(x0,y0+height),(x0+width,y0+height),((x0+hw)*1.01,(y0+hh)*1.01),(x0,y0),(x0,y0),]
        codes1 = [Path.MOVETO,Path.LINETO,Path.LINETO,Path.LINETO,Path.MOVETO,Path.CLOSEPOLY,]
        path1 = Path(verts1,codes1)
        patch1 = mpatches.PathPatch(path1,ls='dashed',ec='red',facecolor="none")

        verts2 = [((x0+hw)*0.99,(y0+hh)*0.99),(x0,y0),(x0+width,y0),(x0+width,y0+height),(x0+hw,y0+hh),(x0,y0),]
        codes2 = [Path.MOVETO,Path.LINETO,Path.LINETO,Path.LINETO,Path.MOVETO,Path.CLOSEPOLY,]
        path2 = Path(verts2,codes2)
        patch2 = mpatches.PathPatch(path2,ls='solid',edgecolor='red', facecolor="none")

        patch = PatchCollection([patch1,patch2],match_original=True)

        handlebox.add_artist(patch)
        return patch


fig = plt.figure()
ax = fig.add_subplot(111)

ax.set_xlim(-2,2)
ax.set_ylim(-2,2)

plt.legend([AnyObject()], ['hellocello'],
           handler_map={AnyObject: AnyObjectHandler()})

plt.show()

这似乎适用于PatchCollection，至少对我而言，matplotlib 版本 1.4.3。结果看起来像，