R devel - Nov 2011 - inaccuracy in man page for duplicated() + anyDuplicated() not working with MARGIN=0

Hi,

In man page for duplicated:

   Value:

      ?duplicated()?: For a vector input, a logical vector of the same
      length as ?x?.  For a data frame, a logical vector with one
      element for each row.  For a matrix or array, a logical array with
      the same dimensions and dimnames.

When 'x' is a matrix or array, the returned value is NOT a logical
array:

   > m <- matrix(c(3,2,7,6,2,7), nrow=3)
   > m
        [,1] [,2]
   [1,]    3    6
   [2,]    2    2
   [3,]    7    7
   > duplicated(m)
   [1] FALSE FALSE FALSE

Only if MARGIN=0 it seems:

   > duplicated(m, MARGIN=0)
         [,1]  [,2]
   [1,] FALSE FALSE
   [2,] FALSE  TRUE
   [3,] FALSE  TRUE

Also, any reason why this doesn't work?

   > anyDuplicated(m, MARGIN=0)
   Error in dim(newX) <- c(prod(d.call), d2) :
     dims [product 1] do not match the length of object [6]

May be it could be equivalent to:

   > anyDuplicated(as.vector(m))
   [1] 5

Thanks,
H.

-- 
Herv? Pag?s

Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M1-B514
P.O. Box 19024
Seattle, WA 98109-1024

E-mail: hpages at fhcrc.org
Phone:  (206) 667-5791
Fax:    (206) 667-1319

> Hi,
> In man page for duplicated:
>    Value:
>       ?duplicated()?: For a vector input, a logical vector of the same
>       length as ?x?.  For a data frame, a logical vector with one
>       element for each row.  For a matrix or array, a logical array with
>       the same dimensions and dimnames.
> When 'x' is a matrix or array, the returned value is NOT a logical
> array:
>    > m <- matrix(c(3,2,7,6,2,7), nrow=3)
>    > m
>         [,1] [,2]
>    [1,]    3    6
>    [2,]    2    2
>    [3,]    7    7
>    > duplicated(m)
>    [1] FALSE FALSE FALSE
> Only if MARGIN=0 it seems:
>    > duplicated(m, MARGIN=0)
>          [,1]  [,2]
>    [1,] FALSE FALSE
>    [2,] FALSE  TRUE
>    [3,] FALSE  TRUE
Indeed. Thank you for pointing this out.
I'll definitely fix that part of the help file.
> Also, any reason why this doesn't work?
>    > anyDuplicated(m, MARGIN=0)
>    Error in dim(newX) <- c(prod(d.call), d2) :
>      dims [product 1] do not match the length of object [6]
well, because the R core colleague enhanced duplicated.array()
to work with MARGIN 0 (and similar cases) did not
update the parallel code in anyDuplicated.array() correspondingly.
> May be it could be equivalent to:
>    > anyDuplicated(as.vector(m))
>    [1] 5
Yes, that's what will happen after I've committed my fixes.

Thank you very much, Herv?!
Martin

[...]
> -- 
> Herv? Pag?s
[...]

(*) having authored anyDuplicated()