[R] Applying function to lots of separate data sets

Laura Quinn laura at env.leeds.ac.uk
Mon Sep 6 03:08:04 CEST 2004


Thank you - I have followed your advice but it then begs a further
question!

I am wanting to plot elements from within the list, but I don't know how
to subscript down so far, I want to plot values from rows(1:10) within,
for instance, mylist[[20]], for columns (1:5).

how can I define these??

Laura Quinn
Institute of Atmospheric Science
School of the Environment
University of Leeds
Leeds
LS2 9JT

tel: +44 113 343 1596
fax: +44 113 343 6716
mail: laura at env.leeds.ac.uk

On Sun, 5 Sep 2004, Duncan Murdoch wrote:

> On Mon, 6 Sep 2004 01:14:40 +0100 (BST), Laura Quinn
> <laura at env.leeds.ac.uk> wrote:
>
> >I have a total mental block and can't find my way around this seemingly
> >simple problem:
> >
> >I have created a function such that:
> >
> >my_answer_1=myfuntion(my_input_1)
> >
> >I am wanting to perform this calculation over a large number of datasets,
> >but am having real difficulty calling and assigning - i think the problem
> >les in the fact that I need to paste for call and assign.
> >
> >this is my best attempt so far..I can't seem to find a way around this...
> >
> >for(i in 1:50)
> >eval(parse(text=paste("my_answer_",i,
> >    "<-myfunction(text=paste("my_input_",i,sep=""))",sep="")))
> >
> >can someone please point out where i am going wrong?
>
> Using paste() to construct variable names is overdone.  It's much
> better to put all of your data into a list in one object, then just
> use lapply() to apply a function to each element of the list.
>
> For examples, see ?lapply.
>
> Duncan Murdoch
>




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