[R] Arguments to order()

[Duncan Murdoch]

On 11-04-23 2:00 PM, David Neu wrote:
> Hi,
>
> The rows of a data frame can be sorted lexicographically as shown in
> this example,
>
> my.df<- data.frame(x=c(1,1,1,2,2), y=c(1,2,3,2,1))
> my.df[order(my.df$x,my.df$y, decreasing=TRUE), ]
>
> however, I'm wondering if it's possible to pass a variable in as the
> first argument to order() so that the actual set of columns used in
> the sort can be easily varied?

Use do.call() to construct the call.

Duncan Murdoch

>
> FWIW, the first argument to order() is of type "..." and page 2 of R
> Language Manual says that "Users cannot easily get hold of objects of"
> this type.
>
> Many thanks for any ideas!
>
> Cheers,
> Dave
>
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