我有一个数据框，需要在所有日期的0：00,1：00,2：00,3：00,4：00,5：00,6：00小时内删除行，只留下17个每天的数字而不是24个。然后我需要从这17个值中计算出每天的最大值，但是我不得不摆脱我不需要的7个小时。这是我已经尝试过的东西
library(dplyr)
library (lubridate)
df <- maximums %>% filter(!grepl("0:00", maximums$date))
任何想法如何摆脱7小时？
> class(maximums$date)
[1] "POSIXct" "POSIXt"
> class(maximums$X8.hour.running.ozone)
[1] "numeric"
date X8.hour.running.ozone
1 2015-01-01 07:00:00 0.028938958
2 2015-01-01 08:00:00 0.028889583
3 2015-01-01 09:00:00 0.029101042
4 2015-01-01 10:00:00 0.029714583
5 2015-01-01 11:00:00 0.030435000
6 2015-01-01 12:00:00 0.031142500
7 2015-01-01 13:00:00 0.032040208
8 2015-01-01 14:00:00 0.032310625
9 2015-01-01 15:00:00 0.031541875
10 2015-01-01 16:00:00 0.030727708
11 2015-01-01 17:00:00 0.029294583
12 2015-01-01 18:00:00 0.029521497
13 2015-01-01 19:00:00 0.029260455
14 2015-01-01 20:00:00 0.028565455
15 2015-01-01 21:00:00 0.028091705
16 2015-01-01 22:00:00 0.027990038
17 2015-01-01 23:00:00 0.028562330
18 2015-01-02 00:00:00 0.029188788
19 2015-01-02 01:00:00 0.030586705
20 2015-01-02 02:00:00 0.030149167
21 2015-01-02 03:00:00 0.030019583
22 2015-01-02 04:00:00 0.030131667
23 2015-01-02 05:00:00 0.029914583
24 2015-01-02 06:00:00 0.029825208
25 2015-01-02 07:00:00 0.030125833
26 2015-01-02 08:00:00 0.030182083
27 2015-01-02 09:00:00 0.029968333
28 2015-01-02 10:00:00 0.029895833
29 2015-01-02 11:00:00 0.030017500
30 2015-01-02 12:00:00 0.030468125
31 2015-01-02 13:00:00 0.030865000
32 2015-01-02 14:00:00 0.030941458
33 2015-01-02 15:00:00 0.030991875
34 2015-01-02 16:00:00 0.031401875
35 2015-01-02 17:00:00 0.032022997
36 2015-01-02 18:00:00 0.032019372
37 2015-01-02 19:00:00 0.032063122
38 2015-01-02 20:00:00 0.031818747
39 2015-01-02 21:00:00 0.031460413
40 2015-01-02 22:00:00 0.031113955
41 2015-01-02 23:00:00 0.029953955
42 2015-01-03 00:00:00 0.028782497
43 2015-01-03 01:00:00 0.027288667
44 2015-01-03 02:00:00 0.026244375
45 2015-01-03 03:00:00 0.025112917
46 2015-01-03 04:00:00 0.024015417
47 2015-01-03 05:00:00 0.022908542
48 2015-01-03 06:00:00 0.022458958
49 2015-01-03 07:00:00 0.022889583
50 2015-01-03 08:00:00 0.022612500
51 2015-01-03 09:00:00 0.023327917
理想情况下，我想回复：
date X8.hour.running.ozone
1 2015-01-01 07:00:00 0.028938958
2 2015-01-01 08:00:00 0.028889583
3 2015-01-01 09:00:00 0.029101042
4 2015-01-01 10:00:00 0.029714583
5 2015-01-01 11:00:00 0.030435000
6 2015-01-01 12:00:00 0.031142500
7 2015-01-01 13:00:00 0.032040208
8 2015-01-01 14:00:00 0.032310625
9 2015-01-01 15:00:00 0.031541875
10 2015-01-01 16:00:00 0.030727708
11 2015-01-01 17:00:00 0.029294583
12 2015-01-01 18:00:00 0.029521497
13 2015-01-01 19:00:00 0.029260455
14 2015-01-01 20:00:00 0.028565455
15 2015-01-01 21:00:00 0.028091705
16 2015-01-01 22:00:00 0.027990038
17 2015-01-01 23:00:00 0.028562330
18 2015-01-02 07:00:00 0.030125833
19 2015-01-02 08:00:00 0.030182083
20 2015-01-02 09:00:00 0.029968333
21 2015-01-02 10:00:00 0.029895833
22 2015-01-02 11:00:00 0.030017500
23 2015-01-02 12:00:00 0.030468125
24 2015-01-02 13:00:00 0.030865000
25 2015-01-02 14:00:00 0.030941458
26 2015-01-02 15:00:00 0.030991875
27 2015-01-02 16:00:00 0.031401875
28 2015-01-02 17:00:00 0.032022997
29 2015-01-02 18:00:00 0.032019372
30 2015-01-02 19:00:00 0.032063122
31 2015-01-02 20:00:00 0.031818747
32 2015-01-02 21:00:00 0.031460413
33 2015-01-02 22:00:00 0.031113955
34 2015-01-02 23:00:00 0.029953955
35 2015-01-03 07:00:00 0.022889583
36 2015-01-03 08:00:00 0.022612500
37 2015-01-03 09:00:00 0.023327917