Matplotlib - axvspan vs subplots

Question

我为沿海工程应用编写了一个pythonic脚本，除其他外，应该输出一个包含两个子图的图形。

问题在于我想使用plt.axvspan（）来遮蔽两个子图的一部分，但由于某种原因它只遮蔽其中一个。

请在下面找到我设置图表的代码部分的摘录以及它当前输出的图（代码后链接）。

感谢您的帮助，对不起，如果这是一个菜鸟问题（但事实上我确实是Python中的新手...以及一般的编程）但我无法在任何地方找到答案其他

随意在代码中添加任何注释。

# PLOTTING
# now we generate a figure with the bathymetry vs required m50 and another figure with bathy vs Hs

#1. Generate plots

fig = plt.figure() # Generate Figure
ax = fig.add_subplot(211) # add the first plot to the figure.
depth = ax.plot(results[:,0],results[:,1]*-1,label="Depth [mDMD]") #plot the first set of data onto the first set of axis.
ax2 = ax.twinx() # generate a secondary vertical axis with the same horizontal axis as the first
m50 = ax2.plot(results[:,0],results[:,6],"r",label="M50 [kg]") # plot the second set of data onto the second vertical axis
ax3 = fig.add_subplot(212) # generate the second subplot
hs = ax3.plot(results[:,0],results[:,2],"g",label="Hs(m)")

#Now we want to find where breaking starts to occur so we shade it on the plot.
xBreakingDistance = results[numpy.argmax(breakingIndex),0]

# and now we plot a box from the origin to the depth of breaking.

plt.axvspan(0,xBreakingDistance,facecolor="b",alpha=0.1) # this box is called a span in matplotlib (also works for axhspan)

# and then we write BREAKING ZONE in the box we just created

yLimits = ax.get_ylim() # first we get the range of y being plotted
yMiddle = (float(yLimits[1])-float(yLimits[0])) / 2 + yLimits[0] # then we calculate the middle value in y (to center the text)
xMiddle = xBreakingDistance / 2 # and then the middle value in x (to center the text)
#now we write BREAKING ZONE in the center of the box.
ax.text(xMiddle,yMiddle,"BREAKING ZONE",fontweight="bold",rotation=90,verticalalignment="center",horizontalalignment="center")

#FIGURE FORMATTING
ax.set_xlabel("Distance [m]") # define x label
ax.set_ylabel("Depth [mDMD]") # define y label on the first vertical axis (ax)
ax2.set_ylabel("M50 [kg]") # define y label on the second vertical axis (ax2)
ax.grid() # show grid
ax3.set_xlabel("Distance[m]") #define x label
ax3.set_ylabel("Hs[m]") # define y label
ax3.grid()
plt.tight_layout() # minimize subplot labels overlapping

# generating a label on a plot with 2 vertical axis is not very intuitive. Normally we would just write ax.label(loc=0)
combined_plots = depth+m50 #first we need to combine the plots in a vector
combined_labels = [i.get_label() for i in combined_plots] # and then we combine the labels
ax.legend(combined_plots,combined_labels,loc=0) # and finally we plot the combined_labels of the combined_plots
plt.savefig("Required M50(kg) along the trench.png",dpi=1000)
plt.close(fig)

输出图：

Answer 1

通过调用plt.axvspan，您告诉matplotlib在当前活动的轴上创建axvspan（即在这种情况下，您创建的最后一个，ax3）

你需要在你希望它出现的两个轴上绘制axvspan。在这种情况下，ax和ax3。

所以，你可以这样做：

ax.axvspan(0,xBreakingDistance,facecolor="b",alpha=0.1)    
ax3.axvspan(0,xBreakingDistance,facecolor="b",alpha=0.1)

或一行：

[this_ax.axvspan(0,xBreakingDistance,facecolor="b",alpha=0.1) for this_ax in [ax,ax3]]

Answer 2

分析代码并且无法重现代码很困难。我建议你建立一个最小的例子。在任何情况下，请注意您正在调用“plt.axvspan（”这是对库的一般调用。

你需要在“ax”和“ax2”中明确说明你想要这个（我认为）。

此外，如果您需要更多控制，请考虑使用补丁（我不知道axvspan）：

import matplotlib.pyplot as plt
import matplotlib.patches as patches

fig1 = plt.figure()
ax1 = fig1.add_subplot(111, aspect='equal')
ax1.add_patch(
    patches.Rectangle(
        (0.1, 0.1),   # (x,y)
        0.5,          # width
        0.5,          # height
    )
)
fig1.savefig('rect1.png', dpi=90, bbox_inches='tight')

在示例中看到对“ax1”的调用？只需制作类似于你的东西。或者只是将axvspan添加到每个图中。