On Mon, 7 Jun 2004, Shin, Daehyok wrote: > The interface for dates in R is a little confusing to me. > I want to create a vector of Date objects from vectors of years, months, and > days. > One solution I found is: > > years <- c(1991, 1992) > months <- c(1, 10) > days <- c(1, 2) > > dates <- as.Date(ISOdate(years, months, days)) > > But, in this solution the ISOdate function converts the vectors into > characters, > which can cause serious performance and memory loss > when the vectors of years, months, and days are huge.
Really? You have measured the loss? A million causes no problem for example, and what are you going to do with a million dates that is instantaneous and worthwhile? And a million dates are hardly going to be unique so you only need to convert the unique values. > I am quite sure there is much better solution for it. What is it? Write your own C code, or make a POSIXlt object directly from the numbers and convert that. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
