[matplotlib] subplot을 그리는 방식

작성일자 : 2024-09-21

Ver 0.1.1

참고 사이트 : wiki docs

subplot() 이용

matplotlib.pyplot.subplot — Matplotlib 3.5.3 documentation

import matplotlib.pyplot as plt

plt.subplot(<rows>, <columns>, 1)

(데이터, 서식 etc)
plt.<parameter>()
...

plt.subplot(<rows>, <columns>, 2)

(데이터, 서식 etc)
plt.<parameter>()
...


plt.subplot(<rows>, <columns>, <index>)

(데이터, 서식 etc)
plt.<parameter>()
...


plt.show()

---

stateless API (objected-based) 이용

import matplotlib.pyplot as plt

fig = plt.figure()

ax = fig.add_subplot(<rows>, <columns>, 1)

(데이터, 서식 etc)
ax.<parameter>()
...

ax = fig.add_subplot(<rows>, <columns>, 2)

(데이터, 서식 etc)
ax.<parameter>()
...

ax = fig.add_subplot(<rows>, <columns>, <index>)

(데이터, 서식 etc)
ax.<parameter>()
...

plt.show()

 

예제)

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0, 2*np.pi, 400)
y = np.sin(x**2)

fig = plt.figure(figsize=(6,5))
fig.set_facecolor("skyblue")

ax = fig.add_subplot(1,2,1)
ax.set_facecolor("blue")
ax.plot(x,y)

ax = fig.add_subplot(1,2,2)
ax.set_facecolor("yellow")

 

---

subplots()

matplotlib.pyplot.subplots — Matplotlib 3.5.3 documentation

import matplotlib.pyplot as plt

fig, ax = plt.figure(<rows>, <columns>)

# 방법1
(데이터, 서식 etc)
ax[0].<parameter>()
...

(데이터, 서식 etc)
ax[1].<parameter>()
...

plt.show()

# 방법2

(데이터, 서식 etc)
ax[0,0].<parameter>()
...

(데이터, 서식 etc)
ax[0,1].<parameter>()
...

plt.show()

 

 

예제1)

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0, 2*np.pi, 400)
y = np.sin(x**2)

fig, axs = plt.subplots(2,2, figsize=(6, 6))

fig.set_facecolor('skyblue')

axs[0,0].set_facecolor('green')
axs[0,0].plot(x,y,color = 'white')


axs[0,1].set_facecolor('blue')
axs[1,0].set_facecolor('yellow')
axs[1,1].set_facecolor('red')

 

예제2)

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0, 2*np.pi, 400)
y = np.sin(x**2)

fig, (ax1, ax2) = plt.subplots(1,2, figsize = (6,4))

fig.set_facecolor("skyblue")
ax1.set_facecolor("blue")

ax1.plot(x,y)

ax2.set_facecolor("yellow")

 

---

subplots2grid

그래프 별로 크기를 달리 하고 싶을 때 적용할 수 있는 방법이다.

matplotlib.pyplot.subplot2grid — Matplotlib 3.9.2 documentation

matplotlib.pyplot.subplot2grid(shape # (<int>, <int>) : Number of rows and of columns of the grid in which to place axis.
                              ,loc  # (<int>, <int>) : Row number and column number of the axis location within the grid.
                              ,rowspan = <number> # defualt = 1, Number of rows for the axis to span downwards.
                              ,colspan = <number> # defualt = 1, Number of columns for the axis to span to the right.
                              ,fig = None # optional, Figure to place the subplot in. Defaults to the current figure.
                              ,**kwargs) # Additional keyword arguments are handed to add_subplot.

 

예제)

import matplotlib.pyplot as plt
import numpy as np

# create plot and set location
fig = plt.figure()
axs1 = plt.subplot2grid((3,3), (0,0), colspan = 2) # Top Left (0,0), merge 2 columns in 3x3 space
axs2 = plt.subplot2grid((3,3), (1,0), rowspan = 2, colspan = 2) # Top Left (1,0), merge 2 rows and columns in 3x3 space
axs3 = plt.subplot2grid((3,3), (0,2), rowspan = 3) # Top Left (0,2), merge 3 rows in 3x3 space

fig.set_facecolor('lightgray')

# graph 1 : y = x * x
x = np.arange(1,10)

axs1.plot(x, x*x)
axs1.set_title('x*x')
axs1.grid()

# graph 2 : box plot
axs2.boxplot(np.random.randn(500,5))
axs2.set_facecolor('#E6F0F8')
axs2.set_title('box plot')

# graph 3 : y = x ** 3
x = np.arange(1,10)

axs3.plot(x, x ** 3)
axs3.set_title('x ** 3')          
axs3.grid(color = 'b', ls = '-.', lw = 0.75) # blue, dot-line, linewidth = 0.75

plt.tight_layout() # input appropriate padding automatically
plt.show()