[R] How to erase (replace) certain elements in the data.frame?

From: sneaffer <sneaffer_at_mail.ru>
Date: Sat, 23 Apr 2011 17:37:51 -0700 (PDT)


Hello R-world,
Please, help me to get round my little mess I have a data.frame in which I'd rather like some values to be NA for the future imputation process.

I've come up with the following piece of code:

random.del <- function (x, n.keeprows, del.percent){   n.items <- ncol(x)
  k <- n.items*(del.percent/100)
  x.del <- x
  for (i in (n.keeprows+1):nrow(x)){
    j <- sample(1:n.items, k)
    x.del[i,j] <- NA
  }
  return (x.del)
}  

The problems is that random.del turns out to be slow on huge samples. Is there any other more effective/charming way to do the same?

Thanks,
Sergey

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Received on Sun 24 Apr 2011 - 05:43:51 GMT

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