Hi [EMAIL PROTECTED] napsal dne 14.07.2008 14:37:36:
> Many thanks for the recent answers to my question about pattern recognition. > The hint to "grep" and the "pattern" argument brought me a big deal forward. > > # Now, I have a data frame: > > DATE <- c("1930-01-01", "1930-01-01", "1930-02-01", "1931-01-01", > "1931-02-01", "1931-03-01") # almost all months until "1999-12-01". Day is > always 01, the same months actually occur several times. > FREQ <- rep(1,6) > ex<- data.frame(DATE,FREQ) > Your DATE is not in Date format. See as.Date ex$Date<-as.Date(ex$DATE) > # I can aggregate it like this: > > ex <- tapply(ex$FREQ, ex$DATE, sum) ex1<-tapply(ex$FREQ, cut(ex$Date, "years"), sum) ex1<-tapply(ex$FREQ, format(ex$Date, "%Y"), sum) gives you yearly aggregates > > # or use"grep" to extract a single year: > # ex[grep(pattern="^1931", ex$DATE),] > > # But how can I aggregate the years such that a barplot would show me the > FREQ per year and not per month? > > barplot(as.vector(ex)) barplot(ex1) could be what you want. Regards Petr > > # Sorry for the bad example, of course my data.frame is much bigger and the > barplot gives me a nice monthly time series of events, but I really only want > the occurrences per year, not per month. > > Grateful for your advice! > Friderike > > ______________________________________________ > 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.