[R] Counting the occurences of a charater within a string
flodel at gmail.com
Fri Dec 2 04:32:44 CET 2011
I used within and vapply:
x <- data.frame(Col1 = c("abc/def", "ghi/jkl/mno"), stringsAsFactors = FALSE)
count.slashes <- function(string)sum(unlist(strsplit(string, NULL)) ==
"/")within(x, Col2 <- vapply(Col1, count.slashes, 1))
Col1 Col21 abc/def 12 ghi/jkl/mno 2
On Thu, Dec 1, 2011 at 1:05 PM, Bert Gunter <gunter.berton at gene.com> wrote:
> ## It's not a data frame -- it's just a vector.
>  "abc/def" "ghi/jkl/mno"
>  "/" "//"
>  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:
>> 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)
>>  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
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> Bert Gunter
> Genentech Nonclinical Biostatistics
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