[R] apply() function: margin argument: "2L" versus "2"

[Rui Barradas]

Hello,

2L is an integer, 2 might be or not. In the case of apply(), there is no 
difference.

All possible values for margin? Any possible(*) combination of the 
dimensions of 'x' in

apply(x, margin, function)

(*) non-null. If, say, x <- array(0, dim=c(2,3,4)) (3dim) then you can 
call any of

apply(x, 1, fun) or apply(x, 2, fun) or apply(x, 3, fun) but not margin=4;
apply(x, 1:2, fun) or apply(x, c(1, 3), fun) or ...
apply(x, 1:3, fun)

Hope this helps,

Rui Barradas

Em 22-06-2012 23:23, Luba G escreveu:
> What is the difference of using 2L versus 2 as the margin argument in the
> apply() function? Where can I find detailed information on all of the
> possible margin arguments?
>
>> x
>       [,1] [,2]
> [1,]    1    2
> [2,]    3    4
> [3,]    5    6
> [4,]    7    8
> [5,]    9   10
>> sqrt(apply(x, *2L*, function(r.st) var(r.st[!is.na(r.st)])))
> [1] 3.162278 3.162278
>> sqrt(apply(x,* 2*, function(r.st) var(r.st[!is.na(r.st)])))
> [1] 3.162278 3.162278
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at 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.