Matplotlib：隐藏在主轴背景后面的 twinx 图

Question

我正在努力展示一个 twinx 轴图和一个主轴图。这是我在做什么：

1. 我创建了主轴和 twinx 轴。
2. 我将主轴的 zorder 设置为比双轴更高的值，因为我希望事件处理程序为主轴选择事件（即跟踪工具栏中的 Y 轴）
3. 然后，我绘制两个图形，位于双轴的补丁隐藏在主轴的背景后面。（我知道这一点，因为如果我取消注释a.patch.set_visible(False)行，我可以看到 twinx 轴图）

但是，我想保留跟踪主轨道 Y 轴和背景的能力，因为它们具有不同的比例。这里有一个最小的例子：

---

import matplotlib
matplotlib.use('TkAgg')
import numpy as np
from numpy import arange, sin, pi
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg
from matplotlib.figure import Figure

import sys
if sys.version_info[0] < 3:
    import Tkinter as Tk
else:
    import tkinter as Tk


root = Tk.Tk()
root.wm_title("Embedding in TK")


f = Figure(figsize=(5, 4), dpi=100)
a = f.add_subplot(111)
a.grid(True)
a.set_facecolor('grey')
aTwin = a.twinx()
aTwin.grid(False)



# PROBLEM HERE # Whenever I uncomment this, "aTwin" axis remains hidden.
# Set "a" axis zorder to higher value so that event handler tracks y axis from "a" and not from "aTwin"
a.set_zorder(aTwin.get_zorder() + 1)

#a.patch.set_visible(False) # Uncomment to show volume, but I lose the background from the main axis. I cannot use twinx axis' background/grid since they are different scales

x = np.arange(0.0, 2, 0.01)
y1 = abs(np.sin(2*np.pi*x))
y2 = 10.2*np.sin(4*np.pi*x)

aTwin.set_ylim(0, 3*max(y1))

a.plot(x, y2)
aTwin.fill_between(x, 0, y1, alpha = 0.4)
a.set_ylabel('between y1 and 0')


# a tk.DrawingArea
canvas = FigureCanvasTkAgg(f, master=root)
canvas.show()
canvas.get_tk_widget().pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)

toolbar = NavigationToolbar2TkAgg(canvas, root)
toolbar.update()

canvas._tkcanvas.pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)

def _quit():
    root.quit()
    root.destroy()

button = Tk.Button(master=root, text='Quit', command=_quit)
button.pack(side=Tk.BOTTOM)

Tk.mainloop()

提前感谢您花时间阅读这个问题。:)

Answer 1

似乎您想打开第一个轴的网格，将其补丁设置为不可见，将双轴的补丁设置为可见，并将其着色为灰色。然后在前面移动原始轴是没有问题的。

import numpy as np
import matplotlib.pyplot as plt

f = plt.figure(figsize=(5, 4), dpi=100)
ax = f.add_subplot(111)
axTwin = ax.twinx()

# Turn grid of a on.
ax.grid(True)
axTwin.grid(False)

# Set ax's patch invisible
ax.patch.set_visible(False)
# Set axtwin's patch visible and colorize it in grey
axTwin.patch.set_visible(True)
axTwin.patch.set_facecolor('grey')

# move ax in front
ax.set_zorder(axTwin.get_zorder() + 1)

x = np.arange(0.0, 2, 0.01)
y1 = abs(np.sin(2*np.pi*x))
y2 = 10.2*np.sin(4*np.pi*x)

axTwin.set_ylim(0, 3*max(y1))

ax.plot(x, y2)
axTwin.fill_between(x, 0, y1, alpha = 0.4)
ax.set_ylabel('between y1 and 0')

plt.show()