[R] Creating functions with a loop.

[David Winsemius]

I think there is much to recommend this approach, but if you still  
want to have separate functions in the workspace with the names having  
successive integer designations then I have  an approach. (There could  
still be storage in a list for these functions with matching named  
indices.)

 > ftxt <- paste("ff.", 1:10, "<- function(x) { ff.", 0:9, "(x) -  
sum(1:j)}", sep="")
 > source(file=textConnection( ftxt[1]) )
 > ff.1
function(x) { ff.0(x) - sum(1:j)}
 > source(file=textConnection( ftxt[2]) )
 > ff.2
function(x) { ff.1(x) - sum(1:j)}

You could sapply over the 'ftxt' vector using the source() function on  
a textConnection.

Clunky, admittedly. And I never got the intended logic, so completely  
untested.

-- 
David.

On May 23, 2012, at 8:59 AM, Rui Barradas wrote:

> Hello,
>
> To keep related objects of the same nature in the same structure  
> makes very good sense but why not name the functions in the list  
> after they were created?
>
> Using 'NextFunc' of a previous post,
>
>
> f.list <- list()
> f.list[[1]] <- function(x) x^2
> f.list[[2]] <- NextFunc(f, 1)
> f.list[[3]] <- NextFunc(f2, 2)
>
> names(f.list) <- paste("ff", 1:3, sep=".")
>
> f.list[[ 3 ]](3) # 6 = 3^2 - 1 - 2
> f.list[[ "ff.3" ]](3) # the same
> f.list$ff.3(3) # the same
>
>
> Hope this helps,
>
> Rui Barradas
> Em 23-05-2012 11:00, "R. Michael Weylandt"  
> <michael.weylandt at gmail.com> escreveu:
>> Date: Tue, 22 May 2012 18:50:08 -0400
>> From: "R. Michael Weylandt"<michael.weylandt at gmail.com>
>> To: Etienne Larriv?e-Hardy 	<etienne.larrivee-hardy.1 at ulaval.ca>
>> Cc:r-help at r-project.org
>> Subject: Re: [R] Creating functions with a loop.
>> Message-ID:
>> 	<CAAmySGMpyobjLP5qHRg3S6UM0C5T08Yn-CUiUg9eQ2SSTobLpw at mail.gmail.com>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> You can do what you want with the get() and assign() functions,  
>> though
>> it might be easier and better to use match.fun() than get()
>>
>> Much better though would be to build your functions in a list and  
>> call
>> the n-th element of the list with syntax like
>>
>> f.list[[3]](4)
>>
>> will call the function in the third element of the list with  
>> argument 4.
>>
>> Best,
>> Michael
>>
>> On Tue, May 22, 2012 at 1:24 PM, Etienne Larriv?e-Hardy
>> <etienne.larrivee-hardy.1 at ulaval.ca>  wrote:
>>> >  Michael's method seems to be working but I still can't get to  
>>> wrap it in a
>>> >  loop since I cannot get the loop to dynamically change the  
>>> functions' name,
>>> >  i.e. ff1, ff2, ff3, ... In other words, I would need the first  
>>> iteration to
>>> >  create the function ff1, the second to create the function  
>>> ff2, ...
>>> >  Furthermore, does anyone know of a way to call said functions  
>>> from a loop in
>>> >  a way that the first step of the loop calls ff1, the second  
>>> calls ff2 and so
>>> >  on?
>>> >
>>> >  The 2 problems should be closely related I think.
>>> >
>>> >  Thanks for the time
>>> >
>>> >  --
>>> >  View this message in context:http://r.789695.n4.nabble.com/Creating-functions-with-a-loop-tp4630896p4630938.html
>>> >  Sent from the R help mailing list archive at Nabble.com.
>>> >
>
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David Winsemius, MD
West Hartford, CT