Try this:
Lines <- "Date,Time,Camera,Volume 57,2009-10-09,5:00:00 PM,MANBRIN_RIVER_NB,210 58,2009-10-09,5:10:00 PM,MANBRIN_RIVER_NB,207 59,2009-10-09,5:20:00 PM,MANBRIN_RIVER_NB,250 60,2009-10-09,5:30:00 PM,MANBRIN_RIVER_NB,193 61,2009-10-09,5:40:00 PM,MANBRIN_RIVER_NB,205 62,2009-10-09,6:00:00 PM,MANBRIN_RIVER_NB,185" # read data DF <- read.csv(textConnection(Lines), as.is = TRUE) library(zoo) library(chron) # convert to zoo z <- zoo(DF$Volume, as.chron(paste(DF$Date, DF$Time), "%Y-%m-%d %H:%M:%S %p")) # convert to ts which makes it regularly spaced and back to zoo zz <- as.zoo(as.ts(z)) # fixup times as converting to ts loses the time class but not the time values time(zz) <- as.chron(time(zz) At this point zz is a regularly spaced zoo object. coredata(zz) are its values and time(zz) are its times. > zz (10/09/09 05:00:00) (10/09/09 05:10:00) (10/09/09 05:20:00) (10/09/09 05:30:00) 210 207 250 193 (10/09/09 05:40:00) (10/09/09 05:50:00) (10/09/09 06:00:00) 205 NA 185 There are further examples in ?merge.zoo and vignette("zoo") Also see R News 4/1 on dates and times. On Thu, Mar 4, 2010 at 4:45 PM, Kindra Martinenko <kmartine...@gmail.com> wrote: > I posted a similar question, but feel it needs a bit more elaboration. > > I have a data frame (read from a csv file) that may have missing rows. Each > day has 7 time intervals associated with it, with a range from 17:00 hrs to > 18:00 hrs in 10 minute bins. > > What I am looking for is a script that will run through the data frame and > insert "NA"in the Volume column for any dates that are missing a time > interval. For example: > > Date Time Camera > Volume > 57 2009-10-09 5:00:00 PM MANBRIN_RIVER_NB 210 > 58 2009-10-09 5:10:00 PM MANBRIN_RIVER_NB 207 > 59 2009-10-09 5:20:00 PM MANBRIN_RIVER_NB 250 > 60 2009-10-09 5:30:00 PM MANBRIN_RIVER_NB 193 > 61 2009-10-09 5:40:00 PM MANBRIN_RIVER_NB 205 > 62 2009-10-09 6:00:00 PM MANBRIN_RIVER_NB 185 > > Note that between row 61 and row 62, there is a missing time interval (5:50 > PM). I want the data frame to look like this: > > Date Time Camera > Volume > 57 2009-10-09 5:00:00 PM MANBRIN_RIVER_NB 210 > 58 2009-10-09 5:10:00 PM MANBRIN_RIVER_NB 207 > 59 2009-10-09 5:20:00 PM MANBRIN_RIVER_NB 250 > 60 2009-10-09 5:30:00 PM MANBRIN_RIVER_NB 193 > 61 2009-10-09 5:40:00 PM MANBRIN_RIVER_NB 205 > *62 2009-10-09 5:50:00 PM MANBRIN_RIVER_NB NA* > 62 2009-10-09 6:00:00 PM MANBRIN_RIVER_NB 185 > > > Thanks in advance, > Kindra > > [[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.