I'm fairly new to R and still learning how to use it. I could really use some help with the following problem.
I have a huge .csv file containing thousands of measurements on 34 different birds. Measurements include longitude, latitude, altitude, speed, time, etc. All birds have a different number (ranging from 121 to 542). All measurements have a tripID (1 for the first trip of every bird, 2 for the second, etc.) I need to create a vector containing only the first measurement of every trip. I need this to see at what time a bird leaves the nest and eventually make a histogram out of that. I need to write a piece of code that would look something like this: bird121trip1 <- (data[which(data$device_info_serial == 121 & [which(data$tripID == 1)] & [which(data$time == "lowest"),] bird121trip2 <- (data[which(data$device_info_serial == 121 & [which(data$tripID == 2)] & [which(data$time == "lowest"),] bird130trip1 <- (data[which(data$device_info_serial == 130 & [which(data$tripID == 1)] & [which(data$time == "lowest"),] etc. trip.departures <- c(bird121trip1, bird121trip2, bird130trip1, etc) I could do it like I described above (although I would have to replace "lowest" with something that actually works), but I have 34 birds and many of them have hundreds of different trips. I'm sure there's an easier and faster way to do that. Any help would be greatly appreciated. Thanks in advance. -- View this message in context: http://r.789695.n4.nabble.com/noob-requesting-help-tp4632803.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.
