R help - Apr 2007 - Finding a single unique item in duplicated vectors

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?
Example:
a  <-  as.character(Cs(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

On Wed, 4 Apr 2007, John Kane 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?

 	setdiff( b, a ) ??
>
> 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?
> Example:
> a  <-  as.character(Cs(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
>
> ______________________________________________
> R-help at stat.math.ethz.ch 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.
>
Charles C. Berry                        (858) 534-2098
                                          Dept of Family/Preventive Medicine
E mailto:cberry at tajo.ucsd.edu	         UC San Diego
http://biostat.ucsd.edu/~cberry/         La Jolla, San Diego 92093-0901

--- 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
> 
> ______________________________________________
> R-help at stat.math.ethz.ch 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.
>