check out the 'sqldf' package. In http://code.google.com/p/sqldf/#Example_4._Join there is an example of a temporal join. Maybe this will work for you.
On Fri, Apr 6, 2012 at 9:56 AM, Edith Mertz <mertz...@gmail.com> wrote: > Found the blunder, last line should have been: > > TideH$dt <- as.chron(paste(TideH$Date, TideH$Time), "%Y%m%d %H%M%S") > > After this I did: > > Fix <- read.csv("Fix times.csv") > Fix[,"Station"] <- as.character(Fix[,"Station"]) > Fix[,"Date"] <- as.Date(Fix[,"Date"],format="%d/%m/%Y") > Fix[,"Time"] <- as.character(Fix[,"Time"]) > Fix[,"Fix.Type"] <- as.character(Fix[,"Fix.Type"]) > > Fix$DateTime<- as.chron(paste(Fix$Date, Fix$Time), "%Y%m%d %H%M%S") > > ds <- Fix$DateTime > Fix$dt <- chron(sub(" .*", "", ds), gsub("[apm]+$|^.* ", "", ds)) + > (regexpr("pm", ds) > 0)/2 > > Which gave an error list: > > Error in convert.dates(dates., format = format[[1]], origin. = origin.) : > format m/d/y may be incorrect > In addition: Warning messages: > 1: In unpaste(dates., sep = fmt$sep, fnames = fmt$periods, nfields = 3) : > 17955 entries set to NA due to wrong number of fields > 2: In convert.dates(dates., format = format[[1]], origin. = origin.) : > NAs introduced by coercion > 3: In convert.dates(dates., format = format[[1]], origin. = origin.) : > NAs introduced by coercion > 4: In convert.dates(dates., format = format[[1]], origin. = origin.) : > NAs introduced by coercion > > Now I'm lost 4sure, help? > > > -- > View this message in context: > http://r.789695.n4.nabble.com/Best-way-to-do-temporal-joins-in-R-tp885420p4537443.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. -- Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. ______________________________________________ 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.