(subplots usage) Matplotlib how to draw multiple subgraphs (axis field)

import matplotlib.pyplot as plt

# Prepare the data .
x=np.arange(3)
y1=np.random.rand((3))
y2=np.random.rand((3))

rough

# Get the plot area and subgraph .
fig,(ax1,ax2)=plt.subplots(1,2,figsize=(10,4))# Specify the drawing area as (10,4), And one row and two columns , By default, the two columns each occupy half , namely (5,4)(5,4)
ax1.plot(x,y1)
ax2.plot(x,y2)

fine

1. scale

The scale sum of the subgraph plt The use of that scale is different .
The latter is :

plt.xticks(x,label)# You can go to x Fill in label value .

But the usage of subgraph is ：

ax1.set_xticks(x)# stay x Mark the number at the position of .
ax1.set_xticklabels(label)# stay x Mark label at .

The effect is as follows ：

# Get the plot area and subgraph .
fig,(ax1,ax2)=plt.subplots(1,2,figsize=(10,4))# Specify the drawing area as (10,4), And one row and two columns , By default, the two columns each occupy half , namely (5,4)(5,4)
ax1.plot(x,y1)
ax2.plot(x,y2)

ax1.set_xticks(x)# stay x Mark the number at the position of .
# ax1.set_xticklabels(label)# stay x Mark label at .

# Get the plot area and subgraph .
fig,(ax1,ax2)=plt.subplots(1,2,figsize=(10,4))# Specify the drawing area as (10,4), And one row and two columns , By default, the two columns each occupy half , namely (5,4)(5,4)
ax1.plot(x,y1)
ax2.plot(x,y2)

ax1.set_xticks(x)# stay x Mark the number at the position of .
label=["a","b","c"]
ax1.set_xticklabels(label)# stay x Mark label at .

2. size

Now we can see , The whole drawing area we set up above is (10,4), Then the default is half , So how to finely control the size of each subgraph ？

# Get the plot area and subgraph .
fig,(ax1,ax2)=plt.subplots(1,2,figsize=(10,4))# Specify the drawing area as (10,4), And one row and two columns , By default, the two columns each occupy half , namely (5,4)(5,4)
ax1.plot(x,y1)
ax2.plot(x,y2)

ax1.set_position((0.1,0.1,0.8,0.8))# take ax1 The lower left corner of is placed in the drawing area 0.1,0.1 Location （0.1 Refers to the drawing area 10% It means ）.ax1 After the lower left corner of is placed , Wide for 80%, High for 80%. Be careful , here ax1 The position of the upper right corner of is 0.9,0.9.
ax2.set_position((0.9,0.9,0.1,0.1))# So here from 0.9 Start , Otherwise it will overlap . Then only account for 0.1, Just finished drawing area .

You can see , A big , One small .

trick

In fact, if you have time , Subgraphs （ Axis domain ） The official document of this class says ,axes Other properties can be seen https://matplotlib.org/stable/api/axes_api.html?highlight=axes#module-matplotlib.axes.
All in all , Have the thought of class ,axes( Subgraphs ) Is in figure( canvas ) Medium . Then why is it difficult to learn when it comes to drawing ？ My feeling is that the official for the convenience of everyone , Building subgraphs , We are not going to construct axes class , Instead, call a variety of methods , For example, above

subplots()

It looks like , Easy to get started , Convenient for novices , But it has greatly damaged the understanding of advanced people , Ah .

According to the thought of class , We should be as follows ：

First create the drawing area object figure, Then pass this object and the location of the subgraph axes Class in the constructor , Get the subgraph . Then draw .