[R] stacking effectively - without loops

[David Winsemius]

On Nov 2, 2010, at 4:58 PM, Dimitri Liakhovitski wrote:

> Never mind - found it: expand.grid(y,x)

Yes, that is one way and is a way that was illustrated yesterday for a  
very similar question on r-help by (perhaps?) Grothendieck). Another  
way is:

data.frame(lets = rep(letters[1:5], each=3), nums=rep(1:3, 5) )

There are at least two different ways that rep() can be invoked and  
each= is not the default.

-- 
david.

>
> On Tue, Nov 2, 2010 at 4:57 PM, Dimitri Liakhovitski
> <dimitri.liakhovitski at gmail.com> wrote:
>> Hello!
>>
>> I have 2 vectors:
>>
>> x<-letters[1:5]
>> y<-1:3
>>
>> Is there a way - without loops - to create a data frame such that we
>> repeat the whole "y" within each level of "x" so that it looks like
>> this:
>>
>> a 1
>> a 2
>> a 3
>> b 1
>> b 2
>> b 3
>> c 1
>> c 2
>> c 3
>>
>> etc?
>>
>> Thank you!
>>
>> --
>> Dimitri Liakhovitski
>> Ninah Consulting
>> www.ninah.com
>>
>
>
>
> -- 
> Dimitri Liakhovitski
> Ninah Consulting
> www.ninah.com
>
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David Winsemius, MD
West Hartford, CT