[R] dynamically creating functions in r

[Sarah Goslee]

Hi,

On Wed, Oct 5, 2011 at 10:57 AM, honeyoak <honeyoak at gmail.com> wrote:
> it is possible to dynamically create functions in R using lists? what I want
> to do is something like this:
>
>      a = list()
>      for (i in 1:10) a[[i]] = function(seed = i) runif(seed)
>
> so that when I call a[i] I get random draws 1,2,....i unfortunately R only
> uses the last i .

I'm not sure I understand what you want. Do you want to set a new seed for
the random number generator, or do you want a random vector of length i
each time?

If the former, I'm not sure why you'd want to do that, but your choice
of variable
names makes me wonder.

If the latter, you just need a bit of clean-up.

     a <- list()
     for (i in 1:10) {
     	a[[i]] <- runif(i)
     }

But that's not dynamically creating a function, so maybe I'm missing the point.

> I would also like to know if there is a run-all function
> without explicitly looping or using lapply. for example if I have a list 'b'
> of functions if I called
>
>      run-all(b)
>
> all the functions in list 'b' would be run
>
> thanks.

What's wrong with lapply? I think we need to know more about what you're
trying to do. You might also want to look at do.call().

Sarah

-- 
Sarah Goslee
http://www.functionaldiversity.org