Hi,
I was wondering if anybody can help me. In the small data set below I would like
to select the index which doesn't contain the letter 'N' in the
variable 'letters'. How can I discard these rows when the letter has a
different position everytime (but the same letter for the whole column)?
index<-c(1,2,3)
letters<-c("CCTTGGAA", "NNTTGGAAT", "AACCTTNN")
z<-data.frame(index,letters)
index letters
1 1 CCTTGGAA
2 2 NNTTGGAAT
3 3 AACCTTNN
Thanks in advance!
Naomi
one way is:
index <- c(1, 2, 3)
let <- c("CCTTGGAA", "NNTTGGAAT", "AACCTTNN")
z <- data.frame(index, let)
index[-grep("N", let)]
# or
z[-grep("N", let), ]
I hope it helps.
Best,
Dimitris
naomi.duijvesteijn at ipg.nl wrote:> Hi,
>
> I was wondering if anybody can help me. In the small data set below I would
like to select the index which doesn't contain the letter 'N' in the
variable 'letters'. How can I discard these rows when the letter has a
different position everytime (but the same letter for the whole column)?
>
> index<-c(1,2,3)
> letters<-c("CCTTGGAA", "NNTTGGAAT",
"AACCTTNN")
> z<-data.frame(index,letters)
>
>
> index letters
> 1 1 CCTTGGAA
> 2 2 NNTTGGAAT
> 3 3 AACCTTNN
>
>
> Thanks in advance!
> Naomi
>
> ______________________________________________
> R-help at 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.
>
--
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus Medical Center
Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
You really should not assign a new value to "letters" since it is a very useful constant vector that allows working with lowercase letters. Notice that Domitris did not copy your code exactly. Next time you start R type letters at the R prompt. You cannot do so now, since you overwrote that constant with your own construction. LETTERS would still work. -- David Winsemius On Feb 13, 2009, at 10:18 AM, naomi.duijvesteijn at ipg.nl wrote:> Hi, > > I was wondering if anybody can help me. In the small data set below > I would like to select the index which doesn't contain the letter > 'N' in the variable 'letters'. How can I discard these rows when the > letter has a different position everytime (but the same letter for > the whole column)? > > index<-c(1,2,3) > letters<-c("CCTTGGAA", "NNTTGGAAT", "AACCTTNN") > z<-data.frame(index,letters) > > > index letters > 1 1 CCTTGGAA > 2 2 NNTTGGAAT > 3 3 AACCTTNN > > > Thanks in advance! > Naomi > > ______________________________________________ > R-help at 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.