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

[Thomas Levine]

As Joshua said, mine was indeed different from yours. And it didn't
work on non-numeric data. But this one seems to work right:

random.del_vec <- function (x, n.keeprows, del.percent){
  del<-function(notkeep){
    k<-floor(length(notkeep)*del.percent/100)
    notkeep[sample.int(length(notkeep),k)]<-NA
    notkeep
  }
  change<-(n.keeprows+1):nrow(x)
   x[change,]<-t(apply(x[change,],1,del))
  x
}

On the other hand, maybe you really didn't want the stratification by row.

Tom

On Sun, Apr 24, 2011 at 8:31 AM, sneaffer <sneaffer at mail.ru> wrote:
> Thanks a lot, guys.
> Thomas, your method is great, precisely the thing I've been looking forward
> to.
> Oh dear, how I love R for those list comprehension tricks!
>
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