This should do it for you: > x <- read.table(textConnection( "Date time > Temperature + 1 2008-6-1 00:00:00 5 + 2 2008-6-1 02:00:00 5 + 3 2008-6-1 03:00:00 6 + 4 2008-6-1 03:00:00 0 + 5 2008-6-1 04:00:00 6 + 6 2008-6-1 04:00:00 0 + 7 2008-6-1 05:00:00 7 + 8 2008-6-1 06:00:00 7"), header=TRUE) > closeAllConnections() > # create datetime > x$dt <- as.POSIXct(paste(x$Date, x$time)) > # create list of duplicate values next to each other > dup <- c(FALSE, diff(x$dt) == 0) > # remove > x[!dup,] Date time Temperature dt 1 2008-6-1 00:00:00 5 2008-06-01 00:00:00 2 2008-6-1 02:00:00 5 2008-06-01 02:00:00 3 2008-6-1 03:00:00 6 2008-06-01 03:00:00 5 2008-6-1 04:00:00 6 2008-06-01 04:00:00 7 2008-6-1 05:00:00 7 2008-06-01 05:00:00 8 2008-6-1 06:00:00 7 2008-06-01 06:00:00
On Sun, Nov 16, 2008 at 1:10 PM, Antje Nöthlich <[EMAIL PROTECTED]> wrote: > Hei R Users, > > i have the following dataframe: > > Datetime Temperature and many more > collumns > 1 2008-6-1 00:00:00 5 > 2 2008-6-1 02:00:00 5 > 3 2008-6-1 03:00:00 6 > 4 2008-6-1 03:00:00 0 > 5 2008-6-1 04:00:00 6 > 6 2008-6-1 04:00:00 0 > 7 2008-6-1 05:00:00 7 > 8 2008-6-1 06:00:00 7 > . . . > . . . > . . . > 3000 2008-8-31 00:00:00 3 > > > the problem is that row 3 & 4 and row 5 & 6 have the same "Datetime" value > but they differ in the values of the "Temperature" column. > Now for the whole dataframe i would like to delete rows that have the same > "Datetime" value as the prior row. > I have tried unique(dataframe), but it does not work here because the rows > are no real duplicates of each other. > thanks in advance for your help! > > Antje > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.