On Mon, 3 Jul 2023 20:08:06 +0000 "Sorkin, John" <jsor...@som.umaryland.edu> wrote:
> # create variable names xxx1 and xxx2. > string="" > for (j in 1:2){ > name <- paste("xxx",j,sep="") > string <- paste(string,name) > print(string) > } > # Creation of xxx1 and xxx2 works > string You need to distinguish between a space separated string and a string vector. A space separated string is a single object that R won't split for you unless you tell it to. (Are you coming from a Unix background? A command line shell will split a space-separated string into a list of words unless you tell it not to do that, but that's because its main job is to convert space separated command lines typed by the operator into lists of command line arguments. R is not like that at all.) What you're getting here is an individual string. You can confirm that by typing: string[1] and still seeing the whole string. You can also type: string[2] and see an NA instead of the second word in the string. Try replacing the _second_ paste() in the example above with a c(). Given individual strings, paste() concatenates its arguments into a string. c() concatenates its arguments into a vector of separate objects. You should still get a variable named `string`, but when you print it whole, the results will look different (R will separate the two strings inside that vector), and you should be able to type string[1] and string[2] and get "xxx1" and "xxx2" respectively. What about Rui's solution, the one that used paste() and got a vector, contrary to what I wrote above? Rui gave a vector to paste(). paste() runs a loop inside it and produces a string for every vector element of it encounters, unless you tell it to collapse the result. > zzz <- paste("j","k",string) Same thing here. paste() adds spaces and returns a string. You need c() to retain "j" and "k" separate from "xxx1" and "xxx2" as individual elements of the vector. It may *look* similar ([1] "j k xxx1 xxx2" vs. [1] "j" "k" "xxx1" "xxx2"), but the resulting objects are different. When in doubt, use str() on an object to see its structure. -- Best regards, Ivan ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.