Read the ... parameter

The best practice is to use list(...) to read the parameters transmitted through ... It will return a list.

Examples:

> es <- function(...) {str(list(...))}

> es()

list()

> es(1)

List of 1

$ : num 1

> es(c(1, 2))

List of 1

$ : num [1:2] 1 2

> es(r=3, c(1, 2))

List of 2

$ r: num 3

$  : num [1:2] 1 2

> es(las=1, xlim=c(1,2))

List of 2

$ las : num 1

$ xlim: num [1:2] 1 2

If you want read the ... both within a function and in interactive mode for example for debugging:

troispoints <- tryCatch(list(...), error=function(e) list())