[R] select same row in a data frame several times

MacQueen, Don macqueen1 at llnl.gov
Fri Nov 14 23:18:50 CET 2014

Sorry, I was too quick.

  A[ match(B, A$ID2) ,]

Don MacQueen

Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550

On 11/14/14, 1:45 PM, "Pedro Mardones" <mardones.p at gmail.com> wrote:

>Dear R user;
>Consider the following toy example
>A <- data.frame(ID1 = c(1,2,3,1,2,3,1,2,3), ID2 =
>c("a","b","c","d","e","f","g","h","i"), stringsAsFactors = FALSE)
>B <- sample(a$ID2, 6, replace = TRUE)
>Lets say B is = "a", "a", "a", "h", "b", "e"
>I want to extract from A the rows where ID2 == B. If I use
>AA <- A[A$ID2 %in% B == TRUE,], I get only 1 row with ID2="a" instead of
>the 3 rows I want.
>Is it possible to easily implement this selection? (same row several
>	[[alternative HTML version deleted]]
>R-help at r-project.org mailing list
>PLEASE do read the posting guide
>and provide commented, minimal, self-contained, reproducible code.

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