try this using strsplit: > x <- round(runif(10)*100000, digits=0) > y <- as.Date(x, origin="1970-01-01") > str(y) Class 'Date' num [1:10] 26551 37212 57285 90821 20168 ... > y1 <- as.character(y) > str(y1) chr [1:10] "2042-09-11" "2071-11-19" "2126-11-04" "2218-08-30" "2025-03-21" "2215-12-22" ... > x <- strsplit(y1, '-') > x[1:3] [[1]] [1] "2042" "09" "11"
[[2]] [1] "2071" "11" "19" [[3]] [1] "2126" "11" "04" > x.1 <- sapply(x, '[', 3) > str(x.1) chr [1:10] "11" "19" "04" "30" "21" "22" "24" "03" "31" "02" > On Tue, May 24, 2011 at 10:19 AM, Kang Min <[email protected]> wrote: > I have another question - > > I'd like to extract dates from a vector of yyyy-mm-dd, so I just want > the dd. > > x <- round(runif(10)*100000, digits=0) > y <- as.Date(x, origin="1970-01-01") > > I tried this based on the code that Jim provided, but it just printed > the whole date. I think I just need to tweak it a little, but haven't > been able to figure it out. > > y[grep("[[:digit:]]{2}$", y)] > > Thanks. > Kang Min > > On May 23, 7:22 am, jim holtman <[email protected]> wrote: >> If you want to only match names of length 6, you will have to use >> thispattern: >> >> > x <- c("ZFHSJK", "ZFHJKZ","ZIOPWE","ZLKJSD","ZKFLPZ", "ZAAAAAAZ", "ZAZ", >> >> + "ZAAAAZAZ", "ZRITEZ") >> >> >> >> >> >> >> >> >> >> > # match exactly values of length 6 >> > len6 <- "^Z[[:alpha:]]{4}Z$" >> >grep(len6, x) >> [1] 2 5 9 >> >> On Sun, May 22, 2011 at 5:10 PM, Kang Min <[email protected]> wrote: >> > Thanks! >> >> > On May 21, 7:09 am, David Winsemius <[email protected]> wrote: >> >> On May 20, 2011, at 11:57 AM, Kang Min wrote: >> >> >> > Hi all, >> >> >> > I'm trying to subset apatternin a vector. Each argument has 6 >> >> > letters, and I need those that start with Z and end with Z. >> >> >> > e.g. >> >> > x <- c("ZFHSJK", "ZFHJKZ","ZIOPWE","ZLKJSD","ZKFLPZ") >> >> >> > I've looked up other discussions but still can't seem to find the >> >> > answer. >> >> >> You may need to study the regex page a bit longer >> >> >> the "^" is the beginning of a string >> >> ".+" will math can arbitrarily long string of anything >> >> and "$" indicates the end of a string >> >> >> > x <- c("ZFHSJK", "ZFHJKZ","ZIOPWE","ZLKJSD","ZKFLPZ") >> >> >grep("^Z.+Z$", x) >> >> [1] 2 5 >> >> >grep("^Z.+Z$", x, value=TRUE) >> >> [1] "ZFHJKZ" "ZKFLPZ" >> >> >> > Thanks. >> >> > Kangmin >> >> >> > ______________________________________________ >> >> > [email protected] mailing list >> >> >https://stat.ethz.ch/mailman/listinfo/r-help >> >> > PLEASE do read the posting >> >> > guidehttp://www.R-project.org/posting-guide.html >> >> > and provide commented, minimal, self-contained, reproducible code. >> >> >> David Winsemius, MD >> >> West Hartford, CT >> >> >> ______________________________________________ >> >> [email protected] mailing >> >> listhttps://stat.ethz.ch/mailman/listinfo/r-help >> >> PLEASE do read the posting >> >> guidehttp://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 guidehttp://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? >> >> ______________________________________________ >> [email protected] mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guidehttp://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. > -- Jim Holtman Data Munger Guru What is the problem that you are trying to solve? ______________________________________________ [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.
