Plots画线

 1 import numpy as np
 2 
 3 linear_data = np.array([1,2,3,4,5,6,7,8])
 4 exponential_data = linear_data**2
 5 
 6 plt.figure()
 7 #画直线和平方后的线
 8 plt.plot(linear_data, \'-o\', exponential_data, \'-o\')
 9 
10 #用红色虚线画另一组点
11 plt.plot([22,44,55], \'--r\')
12 #添加横纵坐标标注和图的标题
13 plt.xlabel(\'Some data\')
14 plt.ylabel(\'Some other data\')
15 plt.title(\'A title\')
16 #用图例项添加图例，因为之前没有给线段定义labels
17 plt.legend([\'Baseline\', \'Competition\', \'Us\'])
18 
19 #填充一次和两次线段之间的空间
20 plt.gca().fill_between(range(len(linear_data)), 
21                        linear_data, exponential_data, 
22                        facecolor=\'blue\', 
23                        alpha=0.25)

 

1 import pandas as pd
2 
3 plt.figure()
4 observation_dates = np.arange(\'2017-01-01\', \'2017-01-09\', dtype=\'datetime64[D]\')
5 observation_dates = map(pd.to_datetime, observation_dates) # trying to plot a map will result in an error
6 plt.plot(observation_dates, linear_data, \'-o\',  observation_dates, exponential_data, \'-o\')

错误代码

TypeError: object of type \'map\' has no len()

 

1 plt.figure()
2 observation_dates = np.arange(\'2017-01-01\', \'2017-01-09\', dtype=\'datetime64[D]\')
3 observation_dates = list(map(pd.to_datetime, observation_dates)) # 把map转换成list来避免错误
4 plt.plot(observation_dates, linear_data, \'-o\',  observation_dates, exponential_data, \'-o\')

 1 x = plt.gca().xaxis
 2 
 3 # 因为日期太长导致横坐标相互遮盖，所以旋转横坐标值45°
 4 for item in x.get_ticklabels():
 5     item.set_rotation(45)
 6 
 7 # 调整坐标系防止横坐标旋转部分被遮盖
 8 plt.subplots_adjust(bottom=0.25)
 9 #添加横纵坐标标注和图标标题
10 ax = plt.gca()
11 ax.set_xlabel(\'Date\')
12 ax.set_ylabel(\'Units\')
13 ax.set_title(\'Exponential vs. Linear performance\')
14 
15 #在文本用添加数学表达式
16 ax.set_title("Exponential ($x^2$) vs. Linear ($x$) performance")