如何在matplotlib中将次轴图布置在主轴图之下？

Question

我正在尝试在两个y轴上绘制两条曲线，如图所示。但是即使我将红色图（压力）的zorder设置为1和2，绿色图（针升力）也会绘制在主轴图上方。

我使用的代码：

import numpy as np
import matplotlib.pyplot as plt
from matplotlib import ticker as tick
data = np.genfromtxt("secondary_axis.dat", skiprows = 2, delimiter = ',')
time = data[:, 0]
pressure = data[:, 1] * 0.006894759086775369
pressure_charge = data[0, 0]
needle_lift = data[:, 2]
figure = plt.figure(figsize=(5.15, 5.15))
figure.clf()
plot = plt.subplot(111)
plot.plot(time, pressure, label = r'\textit{Raw}', zorder = 2)
plot.set_xlabel(r'\textit{X}', labelpad=6)
plot.set_ylabel(r'\textit{Y}', labelpad=6)
primary_ticks = len(plot.yaxis.get_major_ticks())
ax2 = plot.twinx()
ax2.plot(time, needle_lift, color='#4DAF4A', zorder = 1)
ax2.grid(False)
ax2.set_ylabel(r'\textit{Z}', labelpad=6)
ax2.yaxis.set_major_locator(tick.LinearLocator(primary_ticks))
plt.show()

而且数据可在这里

如何使用matplotlib将绿色（针升）图放置在红色图（压力）下方？

使用rc设置更新了代码

import numpy as np
import matplotlib.pyplot as plt
from matplotlib import rc_context
from matplotlib import ticker as tick


def init_plot_dark():
    params = {'backend' : 'agg', 'legend.numpoints' : 1,
    'lines.linewidth' : 1.0, 'lines.linestyle' : '-', 'axes.facecolor' : '#EEEEEE', 'axes.edgecolor' : '#FFFFFF',
    'axes.linewidth' : 0.0, 'axes.grid' : True, 'axes.titlesize' : 'large', 'axes.labelsize' : 12, 'axes.labelweight' : 'normal',
    'axes.labelcolor' : '000000', 'axes.axisbelow' : True, 'polaraxes.grid' : True , 'axes3d.grid' : True,
    'axes.color_cycle' : ('#E41A1C', '#377EB8', '#4DAF4A', '#984EA3', '#FF7F00', '#FFFF33', '#A65628', '#F781BF', '#999999'),
    'xtick.major.size' : 4 ,'xtick.minor.size' : 2 ,'xtick.major.width' : 0 ,'xtick.minor.width' : 0 ,'xtick.major.pad' : 6,
    'xtick.minor.pad' : 6, 'xtick.color' : '#000000' , 'xtick.labelsize' : 10, 'xtick.direction' : 'in',
    'ytick.major.size' : 4, 'ytick.minor.size' : 2 ,'ytick.major.width' : 0 ,'ytick.minor.width' : 0 ,'ytick.major.pad' : 6,
    'ytick.minor.pad' : 6 ,'ytick.color' : '#000000', 'ytick.labelsize' : 10, 'ytick.direction' : 'in',
    'grid.color' : '#FFFFFF', 'grid.linestyle' : '-', 'grid.linewidth' : 0.5, 'grid.alpha' : 1.0,
    'legend.fontsize' : 10, 'legend.borderaxespad' : 0.5, 'legend.shadow' : False, 'legend.frameon' : True}
    plt.rcParams.update(params)

init_plot_dark()

data = np.genfromtxt("secondary_axis.dat", skiprows = 2, delimiter = ',')
time = data[:, 0]
pressure = data[:, 1] * 0.006894759086775369
pressure_charge = data[0, 0]
needle_lift = data[:, 2]
figure = plt.figure(figsize=(5.15, 5.15))
figure.clf()
plot = plt.subplot(111)
plot.plot(time, pressure, label = r'\textit{Raw}', zorder = 2)
plot.set_xlabel(r'\textit{X}', labelpad=6)
plot.set_ylabel(r'\textit{Y}', labelpad=6)
primary_ticks = len(plot.yaxis.get_major_ticks())
ax2 = plot.twinx()
ax2.plot(time, needle_lift, color='#4DAF4A', zorder = 1)
ax2.grid(False)
ax2.set_ylabel(r'\textit{Z}', labelpad=6)
ax2.yaxis.set_major_locator(tick.LinearLocator(primary_ticks))
plt.show()

Answer 1

上面的答案是正确的，但我想写一个更短更简单的答案。

鉴于：

fig, ax1 = plt.subplots()
ax2 = ax1.twiny()

只需添加（在绘图之前或之后的某处）：

ax1.set_zorder(1)  # default zorder is 0 for ax1 and ax2
ax1.patch.set_visible(False)  # prevents ax1 from hiding ax2

Answer 2

您需要将第一个轴的zorder设置为在第二个轴的zorder之上，但是您需要在将它们都绘制后再做。将这两行添加到您的plt.show()

plot.set_zorder(ax2.get_zorder()+1)
plot.patch.set_visible(False)

第一行的zorder正确，但会完全隐藏第二条轴。因此，我们还需要使用第二行删除画布。

编辑

要使用来正确设置网格线rcParams，您可以改为执行以下操作：切换在您的plot轴和您的ax2轴上绘制的那条线（即，在上施加压力ax2并在上抬起针plot），然后更改其轴和刻度标签在哪一侧：

import numpy as np
import matplotlib.pyplot as plt
from matplotlib import rc_context
from matplotlib import ticker as tick


def init_plot_dark():
    params = {'backend' : 'agg', 'legend.numpoints' : 1,
    'lines.linewidth' : 1.0, 'lines.linestyle' : '-', 'axes.facecolor' : '#EEEEEE', 'axes.edgecolor' : '#FFFFFF',
    'axes.linewidth' : 0.0, 'axes.grid' : True, 'axes.titlesize' : 'large', 'axes.labelsize' : 12, 'axes.labelweight' : 'normal',
    'axes.labelcolor' : '000000', 'axes.axisbelow' : True, 'polaraxes.grid' : True , 'axes3d.grid' : True,
    'axes.color_cycle' : ('#E41A1C', '#377EB8', '#4DAF4A', '#984EA3', '#FF7F00', '#FFFF33', '#A65628', '#F781BF', '#999999'),
    'xtick.major.size' : 4 ,'xtick.minor.size' : 2 ,'xtick.major.width' : 0 ,'xtick.minor.width' : 0 ,'xtick.major.pad' : 6,
    'xtick.minor.pad' : 6, 'xtick.color' : '#000000' , 'xtick.labelsize' : 10, 'xtick.direction' : 'in',
    'ytick.major.size' : 4, 'ytick.minor.size' : 2 ,'ytick.major.width' : 0 ,'ytick.minor.width' : 0 ,'ytick.major.pad' : 6,
    'ytick.minor.pad' : 6 ,'ytick.color' : '#000000', 'ytick.labelsize' : 10, 'ytick.direction' : 'in',
    'grid.color' : '#FFFFFF', 'grid.linestyle' : '-', 'grid.linewidth' : 0.5, 'grid.alpha' : 1.0,
    'legend.fontsize' : 10, 'legend.borderaxespad' : 0.5, 'legend.shadow' : False, 'legend.frameon' : True}
    plt.rcParams.update(params)

init_plot_dark()

data = np.genfromtxt("secondary_axis.dat", skiprows = 2, delimiter = ',')
time = data[:, 0]
pressure = data[:, 1] * 0.006894759086775369
pressure_charge = data[0, 0]
needle_lift = data[:, 2]
figure = plt.figure(figsize=(5.15, 5.15))
figure.clf()
plot = plt.subplot(111)
plot.plot(time, needle_lift, color='#4DAF4A', zorder = 1)
plot.set_xlabel(r'\textit{X}', labelpad=6)
plot.set_ylabel(r'\textit{Z}', labelpad=6)
ax2 = plot.twinx()
ax2.plot(time, pressure, label = r'\textit{Raw}', zorder = 2)
ax2.grid(False)
ax2.set_ylabel(r'\textit{Y}', labelpad=6)
primary_ticks = len(ax2.yaxis.get_major_ticks())
plot.yaxis.set_major_locator(tick.LinearLocator(primary_ticks))

plot.yaxis.tick_right()
plot.yaxis.set_label_position("right")

ax2.yaxis.tick_left()
ax2.yaxis.set_label_position("left")

plt.show()