[R] subtract 2 columns in a data.frame

[Peter Dalgaard BSA]

Ulrich Leopold <uleopold at science.uva.nl> writes:

> Dear list,
> 
> could someone point me to the right command to subtract 2 columns in a
> data.frame. Might be a bit embarrassing question. But I cannot figure
> out how to do this simple command in R.

E.g.,

mydata$difference <- mydata$x - mydata$y

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   O__  ---- Peter Dalgaard             Blegdamsvej 3  
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