Hi,
The trick used by duplicated.data.frame() is to transform the supplied
data.frame into a character vector by pasting together the columns using
"\r" as separator. But no precautions are taken to deal with "\r" in
the supplied data.frame. As a consequence it's easy to imagine
situations where duplicated.data.frame() returns an incorrect answer:
> df <- data.frame(a=c("AA", "AA\r"), b=c("\rBBB", "BBB"))
> df
a b
1 AA \rBBB
2 AA\r BBB
> duplicated(df)
[1] FALSE TRUE
Cheers,
H.
> sessionInfo()
R version 3.0.1 (2013-05-16)
Platform: x86_64-unknown-linux-gnu (64-bit)
locale:
[1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C
[3] LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8
[5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8
[7] LC_PAPER=C LC_NAME=C
[9] LC_ADDRESS=C LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
attached base packages:
[1] stats graphics grDevices utils datasets methods base
--
Hervé Pagès
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: hpa...@fhcrc.org
Phone: (206) 667-5791
Fax: (206) 667-1319
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