基本折线图(单变量，多变量)

Plot

一、单变量折线图

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import pandas as pd
import matplotlib.pyplot as plt
#读取数据
ao = pd.read_csv("AO.txt",sep='\s+',header=None, names=['year','month','AO'])  
ao_jan = ao[ao.month==1]
#创建Figure
fig = plt.figure(figsize=(10, 8))
#创建Axes
ax1 = fig.add_subplot(1,1,1)
#绘制折线图
ax1.plot(np.arange(1950,2020,1),ao_jan.AO, 'ko-')
#添加图题
ax1.set_title('1950-2019 January AO Index')
#添加y=0值水平参考线
ax1.axhline(0,ls=':',c='r')
#添加x=1990垂直参考线
ax1.axvline(1990,ls='--',c='g')
plt.show()

输出图形如下：

image-20200702161610554

其中数据格式如下：

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print(ao)
     year  month        AO
0    1950      1 -0.060310
1    1950      2  0.626810
2    1950      3 -0.008128
3    1950      4  0.555100
4    1950      5  0.071577
..    ...    ...       ...
835  2019      8 -0.721770
836  2019      9  0.306200
837  2019     10 -0.082195
838  2019     11 -1.193400
839  2019     12  0.412070

[840 rows x 3 columns]

二、多变量折线图

实际上只是在同一个axes下叠加多个axes.plot()图层

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import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
ao = pd.read_csv("AO.txt",sep='\s+',header=None, names=['year','month','AO'])  
ao_jan = ao[ao.month==1]
ao_feb = ao[ao.month==2]
fig = plt.figure(figsize=(10, 8))
ax1 = fig.add_subplot(1,1,1)
ax1.plot(np.arange(1950,2020,1),ao_jan.AO,'ko-',label='Jan')
ax1.plot(np.arange(1950,2020,1),ao_feb.AO,'rs-',label='Feb')
ax1.set_title('1950-2019 AO Index')
ax1.legend()
plt.show()

image-20200702161610554

测试数据下载地址：点此下载