Equivalent of match for data.frame

Why not something like

lapply(mydf, function(x) match(myarg, x) )
I don't think that is what is intended (it does not give the quoted result 
in 'S'), but I don't actually know (and we were not told what 'S' this 
is).  My guess is that the whole row has to match element by element. 
For that I would hash rows as in duplicated.data.frame.  Something like

match.data.frame <- function(x, table, ...)
     match(do.call("paste", c(x, sep = "\r")),
           do.call("paste", c(table, sep = "\r")), ...)

maybe with some added as.data.frame() calls for safety.
?

Best regards,

Carlos J. Gil Bellosta
http://www.datanalytics.com

On Sat, 2009-01-03 at 07:24 -0500, S?bastien wrote:
Dear R-users,

I am translating a S script into R and having some troubles with the
match function. This function appears to work with vector and data.frame
in S, but not in R, e.g.:
a <- rep((1:4), each = 10)
b <- rep((1:10), times = 4)
mydf <- data.frame(a,b)
myarg <- mydf[1,]
match(myarg, mydf)

# S returns 1 but R returns NA NA

I guess one could use match(interaction(myarg), interaction(mydf)) to do
the job but I was just wondering if there was a more direct function.

Thanks,

Sebastien

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Equivalent of match for data.frame

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