Esteemed R UseRs, Regarding specifying arguments in functions and calling functions within functions:
## beginning ## ## some data ex <- rnorm(10) ex[5] <- NA ## example function Scale <- function(x, method=c("mean", "median")) { scl <- method scl(x) } ## both return NA Scale(ex, method=median) median(ex, na.rm=FALSE) ## both return the median Scale(ex, method="median") median(ex, na.rm=TRUE) ## 1. Why does the use of apostrophes have this effect when calling ## a fucntion within a function? ## 2. What's the canonical use of apostrophes in functions like the above: ## Scale <- function(x, method=c("mean", "median")) {.... ## or ## Scale <- function(x, method=c(mean, median)) {.... ## 3. How does one specify the arguments of a function being called ## within a function? i.e. i thought the use of '...' might work in ## the following but i was wrong. ## '...' has no apparent effect Scale <- function(x, method=c("mean", "median"),...) { scl <- method scl(x) } ## both return NA Scale(ex, method=median, na.rm=TRUE) Scale(ex, method=median, na.rm=FALSE) ## end ## I failed to comprehend anything google returned when trying to understand this myself. Greatly appreciate any thoughts &/or examples on this. Tia, Karl -- Karl Brand Dept of Cardiology and Dept of Bioinformatics Erasmus MC Dr Molewaterplein 50 3015 GE Rotterdam T +31 (0)10 703 2460 |M +31 (0)642 777 268 |F +31 (0)10 704 4161 ______________________________________________ R-help@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.