Hello all, I'm trying to group several consecutives rows (and assigning them the same value) while leaving some of the rows empty (when a certain condition is not fulfilled).
My data are locations (xy coordinates), the date/time at which they were measured, and the time span between measures. Somehow simplified, they look like this: <http://r.789695.n4.nabble.com/file/n4646956/image1.png> I'd like to assign a value to every sequence of locations that are measured within a time span of 4 hours, and make my data look like this: <http://r.789695.n4.nabble.com/file/n4646956/image2.png> I've tried several algorithms with a loop "for" plus "ifelse" condition like: Sequence <- for (i in 1:max(ID)) { ifelse (Span <= 4, i+1, "NA") } without any luck. I know my attempt is incorrect, but my programming skills are really basic and I haven't found any similar problem in the web. Any ideas would be very appreciated! -- View this message in context: http://r.789695.n4.nabble.com/Assigning-values-to-several-consecutives-rows-in-a-sequence-while-leaving-some-empty-tp4646956.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
