Re: [R] Error with lapply [addirional clarification needed]

From: Gabor Grothendieck <ggrothendieck_at_gmail.com>
Date: Sat, 22 Nov 2008 05:16:53 -0500

Try str(ss) to see what it really looks like. You probably want:

fn <- function(i) c(i, i^2)

On Sat, Nov 22, 2008 at 4:54 AM, megh <megh700004_at_yahoo.com> wrote:
>
> I need one more clarification here :
>
> Here I did :
>
> fn <- function(i) return(list(i, i^2))
> ss = sapply(1:4, fn)
>
> Here the object "ss" should be a matrix object :
> is.matrix(ss)
>
> However I feel it lacks some the matrix object properties. For example the
> syntax "min(ss[1,])" generates an error :
> "Error in min(ss[1, ]) : invalid 'type' (list) of argument".
>
> What should be the way out? Am I missing something ?
>
> Regards,
>
>
> baptiste auguie-2 wrote:
>>
>> Hi,
>>
>> you are feeding lapply "i" as an optional argument, which is passed to
>> fn() and causes an error. Just use lapply(1:4, fn), or better yet,
>> sapply,
>>
>> > fn <- function(i) return(i^2)
>> > sapply(1:4, fn)
>> [1] 1 4 9 16
>>
>> Hope this helps,
>>
>> baptiste
>>
>>
>> On 20 Nov 2008, at 16:31, megh wrote:
>>
>>>
>>> I have written following codes, with intention to get a list with
>>> values
>>> 1,2,9,16 :
>>>
>>> fn <- function(i) return(i^2)
>>> lapply(1:4, fn, i)
>>>
>>> However I got following error :
>>> Error in FUN(1:4[[1L]], ...) : unused argument(s) (1)
>>>
>>> Can anyone please tell me what will be the correct code here?
>>>
>>> Regards,
>>>
>>>
>>> --
>>> View this message in context:
>>> http://www.nabble.com/Error-with-lapply-tp20605066p20605066.html
>>> Sent from the R help mailing list archive at Nabble.com.
>>>
>>> ______________________________________________
>>> R-help_at_r-project.org mailing list
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>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
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>>
>> _____________________________
>>
>> Baptiste Auguié
>>
>> School of Physics
>> University of Exeter
>> Stocker Road,
>> Exeter, Devon,
>> EX4 4QL, UK
>>
>> Phone: +44 1392 264187
>>
>> http://newton.ex.ac.uk/research/emag
>>
>> ______________________________________________
>> 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.
>>
>>
>
> --
> View this message in context: http://www.nabble.com/Error-with-lapply-tp20605066p20634821.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
>



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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. Received on Sat 22 Nov 2008 - 10:20:53 GMT

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