[R] Extracting rows of a data.frame by "identical"

[Ivan Calandra]

I'm not sure what you are trying to do...

Have you checked what the output of d[c("b","c")] is? And what about the 
output of identical(d[c("b","c")],c(4,10)) ? As is, I don't see the 
point of going through identical(). Maybe you're looking for which() or 
"%in%"?

If you just want to subset the second row, and second and third columns, 
then just do it! In your code, you forgot to subset for the rows... Here 
is an idea:
d[2, c("b","c")]
You can also use the function subset() as Ulrik has shown you.

HTH,
Ivan

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Le 03/05/2016 à 04:56, jpm miao a écrit :
> Is it possible? I am expecting the result to be the second row of the data
> frame ...
>
>
> d<-data.frame(a=1:3, b=3:5,c=9:11)
>> d
>    a b  c
> 1 1 3  9
> 2 2 4 10
> 3 3 5 11
>> d[identical(d[c("b","c")],c(4,10)),]
> [1] a b c
> <0 rows> (or 0-length row.names)
>
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>
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