On May 24, 2011, at 10:19 AM, Kang Min 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.
Dates are stored as integers. You need to educate yourself about the
differences between the internal and printed representations of R
objects, starting with Dates and datatimes. but also including factors.
You also need to familiarize yourself with coercion functions such as
as.character and as.numeric.
y[grep("[[:digit:]]{2}$", y)] # ????????
One of these would be more in keeping with what you asked for above
> substr(as.character(y), 9,10)
[1] "27" "24" "11" "14" "17" "05" "07" "16" "02" "12"
> format(y, "%d"
+ )
[1] "27" "24" "11" "14" "17" "05" "07" "16" "02" "12"
And please don't persist in appending questions to this thread. It's
no longer about grep.
--
David.
Thanks.
Kang Min
On May 23, 7:22 am, jim holtman <jholt...@gmail.com> wrote:
If you want to only match names of length 6, you will have to use
thispattern:
x <- c("ZFHSJK", "ZFHJKZ","ZIOPWE","ZLKJSD","ZKFLPZ", "ZAAAAAAZ",
"ZAZ",
+ "ZAAAAZAZ", "ZRITEZ")
# match exactly values of length 6
len6 <- "^Z[[:alpha:]]{4}Z$"
grep(len6, x)
[1] 2 5 9
On Sun, May 22, 2011 at 5:10 PM, Kang Min <ngokang...@gmail.com>
wrote:
Thanks!
On May 21, 7:09 am, David Winsemius <dwinsem...@comcast.net> 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
______________________________________________
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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
______________________________________________
r-h...@r-project.org 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.
______________________________________________
r-h...@r-project.org 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?
______________________________________________
r-h...@r-project.org 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.
______________________________________________
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.
David Winsemius, MD
West Hartford, CT
______________________________________________
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.
