R help - Jul 2010 - Creating functions of "many" arguments

Dear users,

My apologies for the simple question. I'd like to create a function where
the number of arguments is as big as the size of my data set. Supose I have
n observations in my data, how can I write a function like

fun <- function (x1,x2,....,xn)  {x1*x2*.......*xn}

Thanks in advance for your help!

Axel.

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On 07/15/2010 08:32 PM, Axel Urbiz wrote:
> Dear users,
>
> My apologies for the simple question. I'd like to create a function
where
> the number of arguments is as big as the size of my data set. Supose I have
> n observations in my data, how can I write a function like
>
> fun<- function (x1,x2,....,xn)  {x1*x2*.......*xn}
You take the 'whole object' approach.

x <- 1:10

sum(x)

for example.  You'll have to be more specific with what you want your
function
to do, since there are many ways to do this sort of thing.

Your specific example can just use 'prod'.

The 'prod' function  uses the '...' construct
which I think is what you are looking for.

However, in concurrence with a previous answer,
it is almost surely going to be a good idea
to change your way of thinking about the problem.

One word in the R world to search for is:
vectorization

On 16/07/2010 02:32, Axel Urbiz wrote:
> Dear users,
>
> My apologies for the simple question. I'd like to create a function
where
> the number of arguments is as big as the size of my data set. Supose I have
> n observations in my data, how can I write a function like
>
> fun<- function (x1,x2,....,xn)  {x1*x2*.......*xn}
>
> Thanks in advance for your help!
>
> Axel.
>
> 	[[alternative HTML version deleted]]
>
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-- 
Patrick Burns
pburns at pburns.seanet.com
http://www.burns-stat.com
(home of 'Some hints for the R beginner'
and 'The R Inferno')