# [R] Using for (i in ...) command with function

Prof Brian Ripley ripley at stats.ox.ac.uk
Thu Jun 17 01:14:42 CEST 2004

```Might this be the issue:

> for(i in 1:10) {i}
>

? Note, no output.  If you want to print the result of final(data, i) ina
for() loop you need to do so explicitly.

A second issue is that your example code defines sum() in terms of sum()
and so is recursive.  You should get the error message

Error in sum(data[, x]) : evaluation nested too deeply: infinite recursion
/ options(expression=)?

At least I do with your code below.

On Wed, 16 Jun 2004, Jennifer Emond wrote:

> Hi,
>
> I have defined a function, and I want to apply this function for
> different values of i, yet, when I use a for command, it only
> executes the function for the first value of i.
>
> My functions are long, but here is an example.  The problem is if I run
> the following code:
>
> tab<-function(data,x){
> a.length<-length(data[,x])
> return(a.length)
> }
>
> sum<-function(data,x){
> b.sum<-sum(data[,x])
> return(b.sum)
> }
>
> final <- function(data,c){
>      if(is.factor(data[,x])==TRUE){
>      tab(data,x)
>    } else{
>      sum(data,c)}
>    }
>
>
> Then try to run:
> for (i in 1:10){
> 	final(data,i)
> }
>
> I get only the output for function for when i=1, and not for each value.

--
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

```