[R] list syntax question: which subscript is which

jim holtman jholtman at gmail.com
Wed Oct 15 03:59:35 CEST 2008


try:

max(sapply(foo, max))


On Tue, Oct 14, 2008 at 5:49 PM, Carl Witthoft <carl at witthoft.com> wrote:
> Hi,
> Sorry to bother with something that should be simple, but I can't find it.
>
> Suppose I have a list, each element of which is a 2xN dataframe, where N
> could be different for each element.
> Is there some simple structure to let me examine all the elements of each
> element's first column?  For example:
>
>>foo
> $first
>     [,1] [,2]
> [1,]    1    4
> [2,]    2    5
> [3,]    3    6
>
> $second
>     [,1] [,2]
> [1,]    1    6
> [2,]    2    8
> [3,]    3    6
> [4,]    4    8
>
> To find the maximum element in all first columns (say, to set the range of a
> plot where all first columns are x-data), I'd like the legal equivalent of
>
>>max(foo[[*]][,1])
> (where here "*" is a wildcard intended to span all elements of foo)
>
> Or do I have to use one of the apply() functions?
>
> thanks
> Carl
>
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?



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