CODEWITHSUNDEEP
r
Philip John
Philip John

Reputation: 5555

R get the particular hour from the time

I have the following data

Num    Date        Time
1      2015.05.21  12:12:12
2      2015.05.22  13:12:12  
3      2015.05.23  14:12:12
4      2015.05.24  15:12:12
5      2015.05.25  16:12:12

By using weekdays(as.Date(data$Date, format='%Y.%m.%d')) I can get the corresponding days of the week. Also by using months I can get the corresponding months. Is there a way to get the hour only in a new column? Something like hours(as.Date(data$Time, format='%H:%M:%S')) which will provide me the following output.

Num    Date        Time      Hour
1      2015.05.21  12:12:12  12
2      2015.05.22  13:12:12  13  
3      2015.05.23  14:12:12  14
4      2015.05.24  15:12:12  15
5      2015.05.25  16:12:12  16

Upvotes: 2

Views: 307

Answers (1)

MrFlick
MrFlick

Reputation: 206187

R doesn't have a native data type for just time values without dates. With the sample data

dd<-read.table(text="Num    Date        Time
1      2015.05.21  12:12:12
2      2015.05.22  13:12:12  
3      2015.05.23  14:12:12
4      2015.05.24  15:12:12
5      2015.05.25  16:12:12", header=T, stringsAsFactors=F)

You can do

transform(dd, Hour=as.POSIXlt(paste(Date, Time), format="%Y.%m.%d %H:%M:%S")$hour)

to get

  Num       Date     Time Hour
1   1 2015.05.21 12:12:12   12
2   2 2015.05.22 13:12:12   13
3   3 2015.05.23 14:12:12   14
4   4 2015.05.24 15:12:12   15
5   5 2015.05.25 16:12:12   16

Upvotes: 2

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