[R] Managing output

[Duncan Murdoch]

On 26/08/2009 4:06 PM, Rolf Turner wrote:
> On 27/08/2009, at 8:00 AM, Duncan Murdoch wrote:
> 
>> 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)
> 
> 	That should be result_list <- numeric(0)!!! :-)

Yep!

Duncan Murdoch

> 
> 		cheers,
> 
> 			Rolf
> 
>> 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
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting- 
>> guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> 
> 
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