Greetings, My data set has dates and times that I am working with. Some of the times in Time_of_end are blank. This is supposed to dictate that the particular experiment lasted 48 hours. I would like to add 48 hours to the start Start_of_Experiment for another column as End_of_Experiment including both the ones with 48 added and those with early times. I was thinking something with a conditional statement but I can't seem to figure out what code to use. Any insight would be appreciated. Let me know if there is anything else you need. Thanks for your time.
I have Start_of_Experiment in POSIX format for time calculations from the following: data$Start_of_Experiment=as.POSIXct(strptime(data$start_time, "%m/%d/%Y %H:%M:%S")) Here is a subset of my data. ID group Start_date Time_of_experiment Time_of_end 1 20209 4 02/02/2009 12:38:00 26 30209 3 03/02/2009 12:40:00 13:32:00 27 31609 4 03/16/2009 11:28:00 12:26:00 28 40609 4 04/06/2009 11:17:00 53 42709 4 04/27/2009 11:15:00 9:30:00 76 51109 3 05/11/2009 11:51:00 101 51809 1 05/18/2009 12:28:00 126 62209 3 06/22/2009 11:31:00 150 71309 4 07/13/2009 12:12:00 13:37:00 173 81009 4 08/10/2009 11:32:00 20:52:00 Start_of_Experiment 1 2009-02-02 12:38:00 26 2009-03-02 12:40:00 27 2009-03-16 11:28:00 28 2009-04-06 11:17:00 53 2009-04-27 11:15:00 76 2009-05-11 11:51:00 101 2009-05-18 12:28:00 126 2009-06-22 11:31:00 150 2009-07-13 12:12:00 173 2009-08-10 11:32:00 [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.