[R] Omiting repeated values

[Oleg Sklyar]

Hi,

'unique' or its combination with 'match' if you need to keep the vector 
the same length will do it:

 > a<-c(1,2,4,2,5,5,6,7,8)
 > unique(a)
[1] 1 2 4 5 6 7 8

 > a[ which( is.na( match(1:length(a), match(unique(a),a)) ) ) ]=NA
 > a
[1]  1  2  4 NA  5 NA  6  7  8
This is probably not the best implementation, but it does the job.

'table' will also give you the number of occurances of unique values:

 > a<-c(1,2,4,2,5,5,6,7,8)
 > table(a)
a
1 2 4 5 6 7 8
1 2 1 2 1 1 1

Oleg

stat stat wrote:
> Dear all R users,
>    
>   Is there any function to omit repeated values in a vector? Your help will be highly appreciated.
>    
>   Thanks 
>   stat
> 
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-- 
Dr Oleg Sklyar * EBI/EMBL, Cambridge CB10 1SD, England * +44-1223-494466