On Aug 12, 2010, at 3:11 PM, Toby Gass wrote:
Dear helpeRs, I have a dataframe (14947 x 27) containing measurements collected every 5 seconds at several different sampling locations. If one measurement at a given location is less than zero on a given day, I would like to delete all measurements from that location on that day. Here is a toy example: toy <- data.frame(CH = rep(3:5,3), DAY = c(rep(4,5), rep(5,4)), SLOPE = c(seq(0.2,0.6, .1),seq(0.2, -0.1, -0.1))) In this example, row 9 has a negative measurement for Chamber 5, so I would like to delete row 6, which is the same Chamber on the same day, but not row 3, which is the same chamber on a different day. In the full dataframe, there are, of course, many more days. Is there a handy R way to do this?
toy[ - which(toy$SLOPE <0 ) , ]
Thank you for the assistance. Toby ______________________________________________ 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.
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.