Awesome,that worked!  Thanks.


On Wed, Mar 16, 2011 at 6:46 AM, Henrique Dallazuanna <wwwhsd@gmail.com>wrote:

> Try this:
>
> mapply('/', l1, l2, SIMPLIFY = FALSE)
>
> and
>
> tapply(1:5, lapply(indxLi, as.numeric), sum)
>
>
> On Tue, Mar 15, 2011 at 6:06 PM, Rohit Pandey <rohitpandey576@gmail.com>
> wrote:
> >
> > Hello R community,
> >
> > I have two questions about using R.
> >
> > The first is about dividing each element of a list with another similar
> > sized list. So, if the first list has two elements and so does the
> second,
> > then the result should also be a list with two elements.
> >
> > For example, the inputs are:
> >
> > list(matrix(1:6,ncol=2),matrix(1:6,ncol=2))->l1
> > l2<-list(1:3,2)
> >
> > I want to get a list, l3 with the first element being l1[[1]]/l2[[1]] and
> > the second one, l1[[2]]/l2[[2]].
> >
> > I had asked a similar question before and the solution using mapply works
> > well for a list and a vector, but for two lists, it will return an array
> > (and not a list).
> >
> > My second question is about the tapply function.
> >
> > tapply(1:5,list(c(1,1,2,2,3),c(1,2,1,1,3)),sum)
> > will give me:
> >
> >   1    2    3
> > 1  1   2  NA
> > 2  7  NA  NA
> > 3 NA  NA   5
> > The index here is a list: list(c(1,1,2,2,3),c(1,2,1,1,3)).
> >
> > However, if I get the same index list through one of the other apply
> > functions (like by) for example,
> > indxLi<-by(rbind(c(1,1,2,2,3),c(1,2,1,1,3)),1:2,function(x){return(x)})
> > then the tapply no longer works with this list.
> > tapply(1:5,indxLi,sum) gives me the error:
> >
> > Error in sort.list(y) : 'x' must be atomic for 'sort.list'
> > Have you called 'sort' on a list?
> >
> > Is there a way to use the above list in the tapply function?
> >
> > Many thanks in advance,
> >
> > --
> > Thanks,
> > Rohit
> > Mob: 91 9819926213
> >
> >        [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help@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<http://www.r-project.org/posting-guide.html>
> > and provide commented, minimal, self-contained, reproducible code.
>
>
>
> --
> Henrique Dallazuanna
> Curitiba-Paraná-Brasil
> 25° 25' 40" S 49° 16' 22" O
>



-- 
Thanks,
Rohit
Mob: 91 9819926213

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