在图形之间移动或复制补丁

如何在图形之间移动（或复制）补丁matplotlib?

我正在处理一组腌制的人物，并想将它们合并到一个情节中。 使用线图时这没有问题，因为我可以通过以下方式访问数据ax.get_lines.

然而，在使用直方图时，ax.get_lines回报<a list of 0 Line2D objects>。据我所知，访问绘制数据的唯一方法是通过ax.patches。 如果我尝试使用以下命令将补丁从一个图形设置为另一个图形ax.add_patch, I get RuntimeError: Can not put single artist in more than one figure.

Edit

我在用着matplotlib2.0.0。 下面的例子说明了问题

import numpy as np
import matplotlib.pylab as plt
import copy

# Creating the two figures
x = np.random.rand(20)
fig1, ax1 = plt.subplots()
fig2, ax2 = plt.subplots()
nr = 0
for color, ax in zip(("red", "blue"), (ax1, ax2)):
    x = np.random.rand(20) + nr
    ax.hist(x, color=color)
    nr += 0.5

# Copying from ax1 to ax2
for patch in ax1.patches:
    patch_cpy = copy.copy(patch)
    # del patch # Uncommenting seems this makes no difference
    ax2.add_patch(patch_cpy)
# RuntimeError: Can not put single artist in more than one figure

I would like to copy the red patches to the figure with the blue patches.

Edit 2

尽管 @ImportanceOfBeingErnest 的答案适用于上述情况，但它不适用于我遇到的现实生活问题。 我最终制作了一个新轴，并手动创建了新补丁，如下所示：

import numpy as np
import matplotlib.pylab as plt
from matplotlib import patches

# Creating the two figures
x = np.random.rand(20)
fig1, ax1 = plt.subplots()
fig2, ax2 = plt.subplots()
nr = 0
for color, ax in zip(("red", "blue"), (ax1, ax2)):
    x = np.random.rand(20) + nr
    ax.hist(x, color=color)
    nr += 0.5

# Create another axis
fig3, ax3 = plt.subplots()

# Copy the properties of the patches to the new axis
for p in ax1.patches:
    ax3.add_patch(patches.Rectangle(p.get_xy(),\
                                    p.get_width(),\
                                    p.get_height(),\
                                    color = "red"))

for p in ax2.patches:
    ax3.add_patch(patches.Rectangle(p.get_xy(),\
                                    p.get_width(),\
                                    p.get_height(),\
                                    color = "blue"))

ax3.autoscale()
plt.show()

显然，仅删除艺术家的旧解决方案在 matplotlib 2.0 中不再起作用。
The patch_cpy仍将连接到与原始轴相同的轴。你可以通过以下方式看到这个print patch_cpy.axes == ax1打印True.

所以解决方案可以是设置axes and figure的属性patch_cpy to None。我必须承认，我不确定这是否有任何副作用，但是，至少下面的例子是有效的。
此外，复制的补丁仍将包含旧轴的数据转换。这需要使用更新patch_cpy.set_transform(ax2.transData).

最后，为了确保绘图限制涵盖旧的和新复制的艺术家，请使用ax2.autoscale().

import numpy as np
import matplotlib.pylab as plt
import copy

# Creating the two figures
x = np.random.rand(20)
fig1, ax1 = plt.subplots()
fig2, ax2 = plt.subplots()

nr = 0
for color, ax in zip(("red", "blue"), (ax1, ax2)):
    x = np.random.rand(20) + nr
    ax.hist(x, color=color)
    nr += 0.5

# Copying from ax1 to ax2
for patch in ax1.patches:
    patch_cpy = copy.copy(patch)
    # cut the umbilical cord the hard way
    patch_cpy.axes = None
    patch_cpy.figure = None
    patch_cpy.set_transform(ax2.transData)
    ax2.add_patch(patch_cpy)

ax2.autoscale()    
plt.show()