Note that this is a common enough case that Hadley provides for it with the str_trim() function in his stringr package.
Best, Michael On Fri, Aug 3, 2012 at 12:02 PM, Bert Gunter <[email protected]> wrote: > "Recursively loop over an object" is a pretty meaningless phrase, > since it depends entirely on the structure of the object. For example, > a character vector is an object, and there is no need for any sort of > recursion to do what you want for it. > > The following regex example trims trailing "spaces" (see ?regex for an > exact definition). Adapt it to whatever structure you like, probably > with apply type functions. > >> x <- c(" ab ","ab \t ","\t\t") >> x > [1] " ab " "ab \t " "\t\t" >> sub("[[:space:]]+$","",x) > [1] " ab" "ab" "" > > But note also that (e.g. S3) methods and is.list or is.recursive may > be useful in a more general approach, something like (where deSpace(x) > is a function with the above sub() expression): > > nospace <- function(x){ > if(is.atomic(x))deSpace(x) > else lapply(x, function(y)Recall(y)) ##?Recall for recursion > } > > Note that this is completely untested, probably fails miserably and > isn't what you want anyway, ... > ;-) > Good luck! > > Cheers, > Bert > > On Fri, Aug 3, 2012 at 9:12 AM, Gene Leynes <[email protected]> wrote: >> My apologies, I know that this is not a new problem, but I'm not sure how >> to find the answer >> >> I want to recursively loop over an object and trim trailing white space. >> When I use this function on a list of data.frame I get output like this: >> [1] "c(\" many spaces \", \" many spaces \")" "c(\" many spaces >> \", \" many spaces \")" >> >> What should I do to recombine the results? >> If anyone has a good way to search for this type of question, that would be >> appreciated. I tried rseek.org with "recursive", but after wading though >> all the rpart references I didn't find something that seemed to help with >> this problem. >> >> Thank you very much. >> >> >> trim <- function(x) { >> if(length(x)>1) sapply(x[1], trim) >> gsub("^[[:space:]]+|[[:space:]]+$", "", x) >> } >> >> tempobj = ' many spaces ' >> tempvec = c(tempobj, tempobj) >> templist = list(tempvec, tempvec) >> tempdf = data.frame(x = tempvec, y = tempvec) >> >> trim(tempobj) >> trim(tempvec) >> trim(templist) >> trim(tempdf) >> >> >> >> >> >> Thank you, >> Gene Leynes >> _____________________________________________ >> *Data Scientist* >> *Mobile: 312-498-7702 >> **http://www.linkedin.com/in/geneleynes >> * >> <http://goog_598053156>*http://geneorama.com/ <http://geneorama.com/%20>* >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> [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. > > > > -- > > Bert Gunter > Genentech Nonclinical Biostatistics > > Internal Contact Info: > Phone: 467-7374 > Website: > http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm > > ______________________________________________ > [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. ______________________________________________ [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.
