First, use stringsAsFactors=FALSE with the read.csv() function. That will prevent the conversion to factors. Then try to convert date and time to datetime objects.
------------------------------------- David L Carlson Department of Anthropology Texas A&M University College Station, TX 77840-4352 -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of tandi perkins Sent: Tuesday, September 30, 2014 12:55 PM To: r-help@r-project.org Subject: [R] Converting factor data into Date-time format Hello R help: I am new to this forum so I apologize in advance for any protocol missteps. I have a data set that is comprised of eight birds with GPS; each of which transmit everyday at 8:00 am, 4:00 pm, and midnight for 1 year (although I have some missing relocation's). I am trying to format my data to be run in adehabitatLT but I am unsuccessful. I have a "csv" file with the following header: "Craneid, Date, Time, Long, Lat, Habitat, BurstID". R creates factor levels in the all of the data except Lat, Long. I have attempted the following to correctly format my date and time factors (data=l10): First attempt: 1. datetime=as.POSIXct(paste(l10$Date, l10$Time), format="%m/%d/%Y %H:%M:%S", "America/Chicago") 2. coord=data.frame((l10$Longitude), (l10$Latitude)) 3. test=as.ltraj(coord, datetime, l10$Craneid, burst=l10$ID, typeII=TRUE) Results:Error in as.ltraj(coord, datetime, l10$Craneid, burst = l10$ID, typeII = TRUE) : non unique dates for a given burst I researched this error on the list serve and found that I could have duplicates so I checked for duplicates in datetime and the return was NULL (I also check for duplicates in Excel as I am in the learning stages in R). Next I read a thread posted on the R help in 2012 with a similar problem so I attempted what was suggested as follows: 1. datetime=as.POSIXct(strptime(as.character(l10$Date, l10$Time), format="%m/%d/%Y %H:%M:%S")) 2.test=as.ltraj(coord, datetime, l10$Craneid, burst=l10$ID, typeII=TRUE) Results: Same error. Finally, I have tried: 1. datetime=as.POSIXct(as.character(levels(l10$Date)(l10$Time)), format="%m/%d/%Y %H:%M:%S")[l10$Date][l10$Time] Results:Error in as.POSIXct(as.character(levels(l10$Date)(l10$Time)), format = "%m/%d/%Y %H:%M:%S") : attempt to apply non-function Can someone please explain what I am doing wrong? My goal is to obtain trajectories for all birds using each bird as a burst as is detailed in the adehabitatLT manual and then to create Bias Random Bridges for each bird. I did not include my data but I can if that will be helpful. Thank you in advance for your help, TLP [[alternative HTML version deleted]] ______________________________________________ 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. ______________________________________________ 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.
