[R] Find strings in a array
Sundar Dorai-Raj
sundar.dorai-raj at pdf.com
Sat Feb 8 21:12:03 CET 2003
Francisco,
Francisco do Nascimento Junior wrote:
> I need to know which strings of an array that are in another array.
> What a best solution?
>
Look at match, pmatch, %in%. Or for regular expressions, regexpr, grep.
For example,
R> x <- c("a", "b", "c")
R> y <- c("a", "b", "d")
R> z <- c("apple", "cantaloupe", "pear")
R> x %in% y
[1] TRUE TRUE FALSE
R> x[x %in% y]
[1] "a" "b"
R>
R> pmatch(x, z, nomatch = 0)
[1] 1 0 2
R> x[pmatch(x, z, nomatch = 0) > 0]
[1] "a" "c"
R>
Sundar
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