I am little lost between all the possibilities to apply a function to a data.frame or data.table.
Here is mine: structure(list(name = c("poisonivy", "poisonivy", "poisonivy", "poisonivy", "poisonivy", "poisonivy", "poisonivy", "poisonivy", "cruzecontrol", "agreenmamba", "agreenmamba", "vairis", "vairis", "vairis", "vairis", "vairis", "vairis", "xaeth"), text = c("ok", "need items ?", "i didn't submit pass codes for a long now", "ok", "<@U03AEKYL4>: what app are you talking about ?", "some testing with my irc client", "ha ha sorry", "for me there is no such question", "Lol.", "<@U03AEKWTL|agreenmamba> uploaded a file: <https://enlightened.slack.com/files/agreenmamba/F03KGRF3W/screenshot_2015-02-09-14-31-15.png|regarding: should I stay or should I go?>", "<@U032FHV3S> <http://youtu.be/oGIFublvDes>", "ok, see you around", "yeah, I had a procrastination rush so I started to decode a little", "<http://ingress.com/intel|ingress.com/intel> when you submit passcodes", "intel", "what is the cooldown time or how does it work...;", "anybody knows how does \"Passcode circuitry too hot. Wait for cool down to enter another passcode.\" works?", "and people told that agent their geocities experience would never amount to anything (the convo yesterday) " ), ts = c("1423594336.000138", "1423594311.000136", "1423594294.000135", "1423594258.000133", "1423594244.000131", "1423497058.000127", "1423497041.000126", "1423478555.000123", "1423494427.000125", "1423492370.000124", "1423478364.000121", "1423594358.000139", "1423594329.000137", "1423594264.000134", "1423594251.000132", "1423592204.000130", "1423592174.000129", "1423150354.000112" )), .Names = c("name", "text", "ts"), class = c("data.table", "data.frame"), row.names = c(NA, -18L)) As you can see, it is of class data.frame and data.table. I need to work on last column "t"s. These are characters and are times in epoch format. I want to have time in Posix. I must thus do two things: - characters to numeric : myData$ts <- as.numeric(myData$ts) - epoch to Posix : mapply(as.POSIXct, tz = 'GMT', origin = '1970-01-01', myMerge$ts) I wonder: - if I can apply these two functions at the same time - what will be the fastest way : use dplyr package, or work with data.table ? My real data will be much more important than the one posted. Thank you for advice and hint. -- google.com/+arnaudgabourygabx ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.