Thanks, that did exactly what I wanted. I realize that I didn't put it in the best form, but was having trouble coming up with a replicable example. I see that many people here quickly create examples and I am learning how to do that, but still struggle, especially when using as.POSIXct and other more complex classes. Thanks for the help.
-----Original Message----- From: dwinsem...@comcast.net [mailto:dwinsem...@comcast.net] Sent: Tuesday, May 10, 2011 10:19 AM To: Thompson, Adele - adele_thomp...@cargill.com Cc: r-help@r-project.org Subject: Re: [R] need to delete by time, not date 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.
