颜色填充matplotlib时间序列图表

Question

考虑以下pandas数据帧:

time                val server   state
2015-01-01 00:00:00 10   server01 normal
2015-01-01 00:02:00 18  server01 high
2015-01-01 00:03:00 41  server01 high
2015-01-01 00:04:00 22  server01 high
2015-01-01 01:05:00 32  server01 normal
2015-01-01 01:06:00 10  server01 high   
2015-01-01 01:07:00 42  server01 normal
2015-01-01 01:08:00 24  server01 normal
...........

在时间序列图上绘制时,如何绘制区域在哪里state = high？

像这样的东西:

Answer 1

由于您只想绘制一个只有一个'high'状态的周期的跨度,您需要建立一个人工缓冲区来分别设置每组的最大值和最小值.

p = pd.Timedelta(30, unit='s')

df.val.plot()
for (state, _), g in df.groupby(['state', df.state.ne('high').cumsum()]):
    if  state == 'high':
        start = g.index.min() - p
        end = g.index.max() + p
        plt.axvspan(start, end, color='r', alpha=0.2)