skewness <- function(x, ...){
if(!is.numeric(x))
stop("x is not numeric")
mean((x-mean(x,...)),...)/(var(x,...))^2
}
x <- rnorm(100)
x[3] <- NA
skewness(x,na.rm=T)
[1] NA
I can not get the answer that I want. So how to use the ellipsis correctly. Especially when it comes to more than one ellipsis that I want to use.