[R] match problem by rownames

[Dimitris Rizopoulos]

try this:

dat <- data.frame(x1 = paste(letters[1:5],10, sep=''), x2=rnorm(5))
row.names(dat) <- dat$x1

dat['a1' %in% row.names(dat), ]
dat['a10'  %in% row.names(dat), ]


I hope it helps.

Best,
Dimitris


> Hi all,
>
> While dat['a1',] and dat['a10',] produce the same results in the
> following example, I'd like dat['a1',] to return NAs.
>
> dat <- data.frame(x1 = paste(letters[1:5],10, sep=''), x2=rnorm(5))
> rownames(dat) <- dat$x1
> dat['a1',]
> dat['a10',]
>
>> sessionInfo()
> R version 2.7.2 (2008-08-25)
> i386-pc-mingw32
>
> locale:
> LC_COLLATE=English_Australia.1252;LC_CTYPE=English_Australia.1252;LC_MON
> ETARY=English_Australia.1252;LC_NUMERIC=C;LC_TIME=English_Australia.1252
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
>
> other attached packages:
> [1] lattice_0.17-13
>
> loaded via a namespace (and not attached):
> [1] grid_2.7.2
>>
>
> Regards,
> Xianming
>
>
>
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-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

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