Hi [EMAIL PROTECTED] napsal dne 27.11.2008 14:20:17:
> Dear useRs, > > I'm struggling again with date-related stuff: I am using R to draw water > levels at certain measuring > stations. My data comes as a tab-delimited text file and looks like this: > > DATUM P1 P2 > ... > 2006-11-16 425.21 423.99 > 2006-12-15 425.12 423.97 > 2007-01-16 425.16 424.06 > ... > > (measurements started in July 2004 and still continue on a monthly or bi-weekly basis) > > This is then plotted using this code: > > a<-read.table("dummy_data.tab", sep="\t", header=TRUE, na.strings=c(0)) > x<-as.Date(a$DATUM) > > plot(x, a$P1, axes=FALSE, xlim=c(as.Date("2004-07-01"), as.Date("2009-01-01")), > ylim=c(423,428), col="red", pch=15, type="o", ylab="Kote [m a.s.l.]", > main="Dummy Plot") > points(x, a$P2, col="red", pch=17, type="o", lty="dotted") > axis(2, at=423:428, tck=1, col="gray60") > axis.Date(1, at=seq(as.Date("2004-07-01"), as.Date("2009-01-01"), > by="month"), labels=seq(as.Date("2004-07-01"), as.Date("2009-01-01"), > by="month"), tck=1, col="gray60") > > So far, I've been using this type of date format (yyyy-mm-dd) because that was > the only way I could > get the whole thing to work when I started using R. However, living in > Switzerland, I would prefer > the dates to read 16.11.2006 i.e. dd.mm.yyyy or 16. Nov. 2006 (preferably > using German names for > the months, if possible). > > I've used the chron package to convert my dates to day mon year (16 Nov 2006, > with or without > spaces), i.e. I replaced the second line of code with: > > x<-format(chron(as.character(a$DATUM), format="y-m-d", out.format="day mon year")) Although I am not an expert in time/date functions it seems to me that you just want your labels to be in your preferred format. If it is the case labels = format(seq(as.Date("2004-07-01"), as.Date("2009-01-01"), by="month"), "%d.%m.%Y") in your call to axisDate can help you to achieve it. Regards Petr > > but then I can't plot them any more, because as.Date() no longer is the > correct function and R gives > me an error saying there is an invalid xlim-value. Can someone please point me > in the right > direction? > > I could easily change the input data to be in dd.mm.yyyy format, if that helps. > > Thanks for your help, > > Kathi > > > -- > DropNet AG - Das Unternehmen fuer Ihren Internet-Auftritt! > > ______________________________________________ > 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.