[R] Managing output

Duncan Murdoch murdoch at stats.uwo.ca
Wed Aug 26 22:00:07 CEST 2009

On 26/08/2009 3:20 PM, Noah Silverman wrote:
> Hi,
> Is there a way to build up a vector, item by item.  In perl, we can 
> "push" an item onto an array.  How can we can do this in R?
> I have a loop that generates values as it goes.  I want to end up with a 
> vector of all the loop results.
> In perl it woud be:
> for(item in list){
>      result <- 2*item^2 (Or whatever formula, this is just a pseudo example)
>      Push(@result_list, result)  (This is the step I can't do in R)
> }
> Thanks!

Use the c() function, e.g.

result <- numeric(0)
for (item in list) {
   result <- 2*item^2
   result_list <- c(result_list, result)

If the list is long, this is an extremely inefficient style of R 
programming, but for a short list it should be fine.

Duncan Murdoch

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