[R] Counting the occurences of a charater within a string

Bert Gunter gunter.berton at gene.com
Thu Dec 1 19:05:03 CET 2011

## It's not a data frame -- it's just a vector.

> x
[1] "abc/def"     "ghi/jkl/mno"
> gsub("[^/]","",x)
[1] "/"  "//"
> nchar(gsub("[^/]","",x))
[1] 1 2


-- Bert

On Thu, Dec 1, 2011 at 8:32 AM, Douglas Esneault
<Douglas.Esneault at mecglobal.com> wrote:
> I am new to R but am experienced SAS user and I was hoping to get some help on counting the occurrences of a character within a string at a row level.
> My dataframe, x,  is structured as below:
> Col1
> abc/def
> ghi/jkl/mno
> I found this code on the board but it counts all occurrences of "/" in the dataframe.
> chr.pos <- which(unlist(strsplit(x,NULL))=='/')
> chr.count <- length(chr.pos)
> chr.count
> [1] 3
> I'd like to append a column, say cnt, that has the count of "/" for each row.
> Can anyone point me in the right direction or offer some code to do this?
> Thanks in advance for the help.
> Doug Esneault
> Privileged/Confidential Information may be contained in this message. If you
> are not the addressee indicated in this message (or responsible for delivery
> of the message to such person), you may not copy or deliver this message to
> anyone. In such case, you should destroy this message and kindly notify the
> sender by reply email. Please advise immediately if you or your employer
> does not consent to email for messages of this kind. Opinions, conclusions
> and other information in this message that do not relate to the official
> business of the GroupM companies shall be understood as neither given nor
> endorsed by it.   GroupM companies are a member of WPP plc. For more
> information on our business ethical standards and Corporate Responsibility
> policies please refer to our website at
> http://www.wpp.com/WPP/About/
> ______________________________________________
> 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.


Bert Gunter
Genentech Nonclinical Biostatistics

Internal Contact Info:
Phone: 467-7374

More information about the R-help mailing list