我是R的新手,我正在尋找一種方法來提取我的數據框中只有小時分鐘和秒鐘。我嘗試了一些庫,但沒有成功。在數據框上提取小時
這裏是我的時刻代碼:
daily_data = read.csv("/Us/eco.csv", header=TRUE, stringsAsFactors=FALSE)
daily_hour= daily_data$time
daily_hour
這是我迄今爲止的樣子如何:
[1] "2016-08-19 17:45:19" "2016-08-19 17:45:19" "2016-08-19 17:45:19" "2016-08-19 17:45:19"
[5] "2016-08-19 18:59:19" "2016-08-19 18:59:19" "2016-08-19 18:59:19" "2016-08-19 18:59:19"
[9] "2016-08-19 18:59:19" "2016-08-19 18:59:19" "2016-08-19 18:59:19" "2016-08-19 18:59:19"
[13] "2016-08-19 19:27:07" "2016-08-19 19:27:07" "2016-08-19 19:27:07" "2016-08-19 19:27:07"
[17] "2016-08-19 19:27:07" "2016-08-19 19:27:07" "2016-08-19 23:33:46" "2016-08-19 23:33:46"
[21] "2016-08-19 23:33:46" "2016-08-19 23:33:46" "2016-08-20 07:13:32" "2016-08-20 07:13:32"
[25] "2016-08-20 07:13:32" "2016-08-20 07:13:32" "2016-08-20 08:52:12" "2016-08-20 08:52:12"
[29] "2016-08-20 08:52:12" "2016-08-20 08:52:12" "2016-08-20 10:06:53" "2016-08-20 10:06:53"
[33] "2016-08-20 10:06:53" "2016-08-20 10:06:53" "2016-08-20 10:06:56" "2016-08-20 10:06:56"
可能的[此]重複(https://stackoverflow.com/questions/36707383/extract-time-from-timestamp)? – simone