[R] Finding a single unique item in duplicated vectors

[John Kane]

--- John Kane <jrkrideau at yahoo.ca> wrote:

> I have a very simple problem and am completely
> missing
> the solution.
> I have two character variables (character ID's from
> two datasets) Data set 'b'
> is data set 'a' with one more subject added.
> How do I find out which is the added subject?
> 
> I have tried duplicated and unique without much
> success.  I can find all the
> duplicated ID's but how do I extract the new
> "unique"
> one?

Amended examaple ( I forgot I had Hmic loaded and was
using it.)
a  <-  as.character(c("b","d","c","a"))
b  <- as.character( Cs("a","b,"c","d","e"))
h  <- c(a,b) ; h
h[duplicated(h)]


> I just want to extract that "e"! 
> 
> I had thought that
> h[!duplicated(h)]
> might work but it simply returns all the unique
> values
> whereas
> I simply want to simply find the odd man out.
> 
> I thought of using sorting the vectors & using a
> cbind
> but the id's are assigned
> more or less randomly so that didn't work.
>  
>  Thanks
> 
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