Python之matplotlib学习（三）

例子11-1：横坐标时间的处理

from matplotlib.dates import datestr2num,DateFormatter
 
import matplotlib.dates as dates
 
fig,ax=plt.subplots()
formatter = DateFormatter('%H')
#设置时间间隔
ax.xaxis.set_major_locator(dates.HourLocator(byhour=range(24), interval=4))
ax.xaxis.set_major_formatter(formatter)
ax.plot_date(datestr2num(time_list),iops_list,'-',label='iops')

输出结果：

例子11-2：纵坐标处理

原图：

从图上看纵坐标区间过大，不利用查看。

改成200为步长：

import matplotlib.ticker as tk
 
ax.yaxis.set_major_locator(tk.MultipleLocator(200)) 

输出结果：

例子11-3：纵坐标处理——按照分钟进行间隔

如下是原始输出的图

时间轴每5分钟一次，过于太密，想改成如下效果：

按照分钟级别进行汇总，代码修改的地方如下：

import matplotlib.dates as dates
ax.xaxis.set_major_locator(dates.MinuteLocator(byminute=range(60), interval=10))
 
>>> import matplotlib.dates as dates
>>> help(dates)
 
#查看帮助文档
Here are all the date tickers:
     
        * :class:`MinuteLocator`: locate minutes
     
        * :class:`HourLocator`: locate hours
     
        * :class:`DayLocator`: locate specifed days of the month
     
        * :class:`WeekdayLocator`: Locate days of the week, eg MO, TU
     
        * :class:`MonthLocator`: locate months, eg 7 for july
     
        * :class:`YearLocator`: locate years that are multiples of base
     
 
     |  ----------------------------------------------------------------------
     |  Data and other attributes inherited from DateLocator:
     |  
     |  hms0d = {'byhour': 0, 'byminute': 0, 'bysecond': 0}