# [R] Simple - Finding vector in a vector

Jessica Streicher j.streicher at micromata.de
Mon Oct 8 16:19:01 CEST 2012

```> x<-c(NA , 1 ,NA,  1 , 1 , 1 , 1 , 1  ,1 ,NA , 1)
> embed(x,3)
[,1] [,2] [,3]
[1,]   NA    1   NA
[2,]    1   NA    1
[3,]    1    1   NA
[4,]    1    1    1
[5,]    1    1    1
[6,]    1    1    1
[7,]    1    1    1
[8,]   NA    1    1
[9,]    1   NA    1

> which(rowSums(embed(x,3))==3)
[1] 4 5 6 7

gives you the first of the 3

On 08.10.2012, at 15:38, Mike Spam wrote:

> Sorry, i just realized, that it output the sum of all vectors. I can
> work with this function but it would be much faster and easier if it
> would be possible to get the positions of evry match.
>
> example:
>
> NA  1 NA  1  1  1  1  1  1 NA  1
>
> rle returns
> lengths: int [1:6] 1 1 1 6 1 1
>
> what i need would be something like,
> 1 1 1 3 3 3 3 1 1
>
> but anyway i can work with rle, if there is no suitable function.
>
> thanks,
> Nico
>
>
>
> 2012/10/8 Mike Spam <ichmagspam at googlemail.com>:
>> Hey Rui,
>>
>> Perfect! Thanks!! :)
>>
>> Nico
>>
>>> Hello,
>>>
>>> See ?rle
>>>
>>> Hope this helps,
>>>
>>> Em 08-10-2012 13:55, Mike Spam escreveu:
>>>>
>>>> Hi,
>>>>
>>>> just a simple question.
>>>> Assumed i have a vector,
>>>>
>>>> FALSE  TRUE  TRUE  TRUE FALSE  TRUE FALSE  TRUE FALSE
>>>> or
>>>> NA  1  1  1 NA  1 NA  1 NA
>>>>
>>>> what i need is the position where an element is the same - three (or
>>>> in general multiple) times in a row.
>>>>
>>>> in this case: i want to get the position where it is TRUE TRUE TRUE or 1 1
>>>> 1
>>>> it doesn't matter if it is the first, middle or last element. So the
>>>> output could be 2 or 3 or 4
>>>>
>>>> My idea would be to lag the vector and calc differences... but i would
>>>> prefer any build in (or time saving) function. :)
>>>>
>>>> thanks,
>>>>
>>>> Nico
>>>>
>>>> ______________________________________________
>>>> R-help at r-project.org mailing list
>>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>>> http://www.R-project.org/posting-guide.html
>>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>>
>
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