On May 10, 2011, at 11:06 AM, Schatzi wrote:
I have a matrix where one column has a date and another column has a
time. I
need to delete all times before 6am. I had combined the Date and
Time column
into DateTime.
Mat1:
Weight Date Time
7.6 04/28/11 09:03
8.4 04/29/11 03:11
8.6 04/29/11 05:32
8.6 04/29/11 09:53
1.4 05/01/11 19:52
I tried just picking up the time:
as.POSIXct(Mat1$Time, format = "%H:%M")
but this assigns the time value today's date.
Since these are either character strings (or factors) at the
moment ... and if they are matrices they are character...
Mat1[Mat1$Time >= "06:00" , ]
If actually a dataframe then
Mat1[as.character(Mat1$Time) >= "06:00" , ]
In the future please include the output of dput(Mat1).
The final matrix should look like:
Weight Date Time
7.6 04/28/11 09:03
8.6 04/29/11 09:53
1.4 05/01/11 19:52
David Winsemius, MD
West Hartford, CT
______________________________________________
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.
