Thanks, is the same possible using basic gsub/sub/grep etc. functions? -J
2010/1/2 Gabor Grothendieck <[email protected]>: > Try this which uses a slightly simpler regexp: > >> library(gsubfn) >> strapply(txt, "(\\d{1,2}\\.\\d{1,2}\\.\\d{4}).*")[[1]] > [1] "05.12.2009" > > or we could convert it to Date class at the same time where we have > assumed month.day.year: > >> strapply(txt, "(\\d{1,2}\\.\\d{1,2}\\.\\d{4}).*", ~ as.Date(x, >> "%m.%d.%Y"))[[1]] > [1] "2009-05-12" > > or this even simpler regexp extracting all the dates and then picking > off the first: > >> strapply(txt, "\\d{1,2}\\.\\d{1,2}\\.\\d{4}")[[1]][1] > [1] "05.12.2009" > > On Sat, Jan 2, 2010 at 10:08 AM, johannes rara <[email protected]> wrote: >> I would like to extract first date from a string: >> >>> txt <- "first date is 05.12.2009. Second date is 06.12.2009." >>> txt >> [1] "first date is 05.12.2009. Second date is 06.12.2009." >> >> I tried: >> >>> sub("^.*?\\s(\\d{1,2}\\.\\d{1,2}\\.\\d{4})", "\\1", txt, extended=T, perl=T) >> [1] "05.12.2009. Second date is 06.12.2009." >>> >> >> How to modify this? >> >> -J >> >> ______________________________________________ >> [email protected] 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. >> > ______________________________________________ [email protected] 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.
