划分画布的主要函数（第一部分）–subplot函数
首先引入一个概念：子区：顾名思义就是将画布分成若干个子画布，这些子画布构成绘图区域，在这些 绘图区域上分别绘制图 形，实现一张画布多张图形分区域展示的效果。
如下图所示：一张画布划分成三个区域，展示三张图形

1. 函数功能

    Add a subplot to the current figure.在当前画布中增加子图。

2. 函数语法

subplot(nrows, ncols, index, **kwargs)
subplot(pos, **kwargs)
subplot(**kwargs)
subplot(ax)

3. 函数参数与示例

参数	含义
(nrows, ncols, index)	子图的位置；画布被划分成 nrows和ncols；索引 index从左上位置1开始，向右增加；索引index也可以是元组，如（3，1，(1，2））表示画布被划分成3行1列，占据索引位置为1，2的位置；当index的数量小于9可以省略逗号"，"。即：（3，2，5）可以写为(325)
projection	绘图区域的投影类型；默认rectilinear；{None, ‘aitoff’, ‘hammer’, ‘lambert’, ‘mollweide’, ‘polar’, ‘rectilinear’, str}
polar	布尔值，绘图区域的投影类型；默认取值False；当取值维True时，为极区图；等价于projection=‘polar’
sharex，sharey	取值为子区，同哪个子区的x或y轴保持一样的边界、刻度

3.1 参数（int，int，index）

3.1.1 index为单个数字

import matplotlib.pyplot as plt
import numpy as npx = np.linspace(-2*np.pi,2*np.pi,1000)
y1 = np.sin(x)
y2 = np.cos(x)plt.subplot(1,2,2)
plt.plot(x,y1)plt.show()

3.1.2 索引为元组

import matplotlib.pyplot as plt
import numpy as npx = np.linspace(-2*np.pi,2*np.pi,1000)
y1 = np.sin(x)
y2 = np.cos(x)plt.subplot(1,3,(1,2))
plt.plot(x,y1)plt.show()

从图中可以看到图形占到整个画布的2/3,是将画布等分成3部分，图形占据1-2两部分。

3.1.3 三维整数

该数字会被解读为为三个单位整数分别给出，如（235）与（2，3，5）是一样的，但是需要注意这种方法只能在小于等于9个子图的情况下使用（超过9个子图第三个参数就会变成两位数）如：（4，3，10）只能使用第一种加分割号的方法，而不能使用（4310）

争取使用（4，3，10）的写法

import matplotlib.pyplot as plt
import numpy as npx = np.linspace(-2*np.pi,2*np.pi,1000)
y1 = np.sin(x)
y2 = np.cos(x)plt.subplot(4,3,(10))
plt.plot(x,y1)plt.show()

当使用（4310）

3.2 参数 projection

import matplotlib.pyplot as plt
import numpy as npx = np.linspace(-2*np.pi,2*np.pi,1000)
y1 = np.sin(x)
y2 = np.cos(x)plt.subplot(3,3,1,projection=None)
plt.plot(x,y1)plt.subplot(3,3,2,projection='polar')
plt.plot(x,y2)plt.subplot(3,3,3,projection='aitoff')
plt.plot(x,y1)plt.subplot(3,3,4,projection='hammer')
plt.plot(x,y2)plt.subplot(3,3,5,projection='lambert')
plt.plot(x,y1)plt.subplot(3,3,6,projection='mollweide')
plt.plot(x,y2)plt.subplot(3,3,7,projection='rectilinear')
plt.plot(x,y1)plt.show()

3.3 参数 polar

'''
import matplotlib.pyplot as plt
import numpy as np
import matplotlib as mplmpl.rcParams['font.sans-serif'] = ['KaiTi']
mpl.rcParams['axes.unicode_minus'] = Falsex = np.linspace(0, 2 * np.pi, 500)
y1 = np.sin(x) * np.cos(x)
y2 = np.exp(-x)
y3 = np.sqrt(x)
y4 = x / 4fig, ax = plt.subplots(4, 1, facecolor='beige', sharex=True,subplot_kw=dict(facecolor='seashell'))fig.subplots_adjust(left=0.05, right=0.98, bottom=0.05,top=0.95, hspace=0)ax[0].plot(x, y1, c='r', lw=2)
ax[1].plot(x, y2, c='y', ls="--")
ax[2].plot(x, y3, c='g', ls=":")
ax[3].plot(x, y4, c='m', ls='-.', lw=2)plt.show()
'''import numpy as np
import matplotlib.pyplot as plt
import matplotlib as mplplt.rcParams['font.sans-serif'] = ['Microsoft YaHei']a = np.linspace(0, 2.0 * np.pi, 10, endpoint=False)
b = [382, 340, 250, 235, 87, 86, 84, 82, 64, 22]
city = ['深圳', '广州', '呼和浩特', '北京', '佛山', '郑州', '南京', '汉中', '西安', '赤峰']
plt.subplot(111, polar=True)
plt.bar(a, b, width=0.2 * np.pi, tick_label=city,color=['skyblue', 'pink', 'y', 'r', 'g', 'm', 'c', 'purple', 'b', 'darkorange'])plt.show()

3.4 参数 sharex、sharey

'''
import matplotlib.pyplot as plt
import numpy as np
import matplotlib as mplmpl.rcParams['font.sans-serif'] = ['KaiTi']
mpl.rcParams['axes.unicode_minus'] = Falsex = np.linspace(0, 2 * np.pi, 500)
y1 = np.sin(x) * np.cos(x)
y2 = np.exp(-x)
y3 = np.sqrt(x)
y4 = x / 4fig, ax = plt.subplots(4, 1, facecolor='beige', sharex=True,subplot_kw=dict(facecolor='seashell'))fig.subplots_adjust(left=0.05, right=0.98, bottom=0.05,top=0.95, hspace=0)ax[0].plot(x, y1, c='r', lw=2)
ax[1].plot(x, y2, c='y', ls="--")
ax[2].plot(x, y3, c='g', ls=":")
ax[3].plot(x, y4, c='m', ls='-.', lw=2)plt.show()
'''import matplotlib.pyplot as plt
import numpy as np
import matplotlib as mplmpl.rcParams['font.sans-serif'] = ['KaiTi']
mpl.rcParams['axes.unicode_minus'] = Falsex1 = np.linspace(0, 2 * np.pi, 500)
y1 = np.sin(x1)
x2 = np.arange(-5, 5)
y2 = np.exp(x2)
x3 = np.linspace(-3, 3)
y3 = np.power(x3, 2)plt.subplot(221)
plt.plot(x1, y1, c='y')
ax2 = plt.subplot(222)
plt.plot(x2, y2, c='c')
plt.subplot(2, 2, (3, 4), sharex=ax2)
plt.plot(x3, y3, c='m')plt.show()

3.5 其他参数

'''
import matplotlib.pyplot as plt
import numpy as np
import matplotlib as mplmpl.rcParams['font.sans-serif'] = ['KaiTi']
mpl.rcParams['axes.unicode_minus'] = Falsex = np.linspace(0, 2 * np.pi, 500)
y1 = np.sin(x) * np.cos(x)
y2 = np.exp(-x)
y3 = np.sqrt(x)
y4 = x / 4fig, ax = plt.subplots(4, 1, facecolor='beige', sharex=True,subplot_kw=dict(facecolor='seashell'))fig.subplots_adjust(left=0.05, right=0.98, bottom=0.05,top=0.95, hspace=0)ax[0].plot(x, y1, c='r', lw=2)
ax[1].plot(x, y2, c='y', ls="--")
ax[2].plot(x, y3, c='g', ls=":")
ax[3].plot(x, y4, c='m', ls='-.', lw=2)plt.show()
'''import matplotlib.pyplot as plt
import numpy as np
import matplotlib as mplmpl.rcParams['font.sans-serif'] = ['KaiTi']
mpl.rcParams['axes.unicode_minus'] = Falsex1 = np.linspace(0, 2 * np.pi, 500)
y1 = np.sin(x1)
x2 = np.arange(-5, 5)
y2 = np.exp(x2)plt.subplot(121, facecolor='lightgreen')
plt.plot(x1, y1, c='y')
ax2 = plt.subplot(122, facecolor='y')
plt.plot(x2, y2, c='c')plt.show()

4. 返回值

返回值的类型取决于projection参数指定的投影类型，当projection=rectilinear 时，返回axes

官方文档subplot