[R] compare and replace

Ben Bolker bbolker at gmail.com
Sat Nov 6 17:49:30 CET 2010

Robert Ruser <robert.ruser <at> gmail.com> writes:

> Hello R Users,
> I'm wondering if there exists any elegant and simple way to do the
> following: I have a data.frame X fills in numbers. I have a vector y with
> numbers as well. Every value in X that is equal to any values in y should
> be replaced by e.g. 1. Any idea?
> Robert

  If the data frames are completely filled with numbers you
should be able to operate on them as matrices (?as.matrix,

X <- matrix(1:16,nrow=4)
Y <- matrix(rep(2:5,4),nrow=4)

(X[X %in% c(Y)] <- 1)

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