> > apply() operates on arrays and a data frame will be coerced to a matrix > (which requires all elements to be of the same type). This is documented in > ?apply. >
Thanks, I was not aware of that. I implicitly assumed there would be a specific apply.data.frame. > This may not be elegant, but why not just use a loop: > The thing is that were are going to use this operation on a (very) large scale in a production environment, on datasets for which nrow >> ncol. So I would like the most efficient solution and if possibly, avoid looping over the rows. Thanks Jeroen [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.