Within a function deparse(substitute(x)) will give the name of x, as a character variable. Search the archives for deparse substitute to find many examples.
On 8/17/07, david dav <[EMAIL PROTECTED]> wrote: > Dear R list, > After a huge delay, I come back to this question. Using names of > variables inside a function is a problem I run into quite often. > Maybe this little example should help to get my point: > Suppose I want to make a function "llabel" to get the labels of the > variables from a data frame. > If no label is defined, "llabel" should return the name of the variable. > > library(Hmisc) > v1 <- c(1,2) > v2 <- c(1,2) > v3 <- c(1,3) > tablo <- data.frame(v1,v2,v3) > rm(v1,v2,v3) > > label(tablo$v1) <- "var1" > attach(tablo) > > # This does the trick on one variable. > if (label(v1) !="") label(v1) else names(data.frame(v1)) > if (label(v2) !="") label(v2) else names(data.frame(v2)) > > But if I call this statement in a "llabel" function, > > llabel <- function(var) { > if (label(var) !="" ) > res <- label(var) > else res <- names(data.frame(var)) > return (res) } > > I just get "var"s instead of the names when no label is defined : > > llabel(v1) # works > llabel(v2) # gives "var" instead of "v2" > > Thanks for your help. > > David > > > 2007/6/7, Uwe Ligges <[EMAIL PROTECTED]>: > > Not sure what you are going to get. Can you shorten your functions and > > specify some example data? Then please tell us what your expected result is. > > > > Best, > > Uwe Ligges > > > > > > > > > > david dav wrote: > > > Dear all, > > > > > > I 'd like to keep the names of variables when calling them in a function. > > > An example might help to understand my problem : > > > > > > The following function puts in a new data frame counts and percent of > > > a data.frame called as "tablo" > > > the step " nom.chiffr[1] <- names(vari) " is useless as names from the > > > original data.frame aren't kept in the function environement. > > > > > > Hoping I use appropriate R-vocabulary, I thank you for your help > > > > > > David > > > > > > descriptif <- function (tablo) { > > > descriptifvar <- function (vari) { > > > table(vari) > > > length(vari[!is.na(vari)]) > > > chiffr <- > > > cbind(table(vari),100*table(vari)/(length(vari[!is.na(vari)]))) > > > nom.chiffr <- rep(NA, dim(table(vari))) > > > if (is.null(names(vari))) nom.chiffr[1] <- paste(i,"") else > > > nom.chiffr[1] <- names(vari) > > > chiffr <- data.frame ( names(table(vari)),chiffr) > > > rownames(chiffr) <- NULL > > > chiffr <- data.frame (nom.chiffr, chiffr) > > > return(chiffr) > > > } > > > > > > res <- rep(NA, 4) > > > for (i in 1 : ncol(tablo)) > > > res <- rbind(res,descriptifvar(tablo[,i])) > > > colnames(res) <- c("variable", "niveau", "effectif", "pourcentage") > > > return(res[-1,]) > > > } > > > # NB I used this function on a data.frame with only factors in > > > > > > ______________________________________________ > > > R-help@stat.math.ethz.ch 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. > > > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > ______________________________________________ R-help@stat.math.ethz.ch 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.