Thanks David for the details and pointer to bitops functions. Buried a bit deep that was. I like to think the memory constraints of win xp keeps my code lean and efficient. RAM is like a suburban garage, the bigger it is, the more useless junk people stuff in there.
Michael Folkes -----Original Message----- From: David Winsemius [mailto:dwinsem...@comcast.net] Sent: March 13, 2012 5:25 PM To: Folkes, Michael Cc: r-help@r-project.org Subject: Re: [R] Amount of memory occupied by data type On Mar 13, 2012, at 7:02 PM, Folkes, Michael wrote: > Hello all, > I was under the (false?) assumption that an object that is class > logical, would take up less memory than an object with class integer. Nope. > Below am I correctly showing this is not the case? > > This was an attempt to reduce memory usage. I think there is a package that will do bitwise operations. Yep... all we needed to do is look: http://finzi.psych.upenn.edu/R/library/bitops/html/00Index.html > I'm dealing with two large > arrays (could be integers). Their contents are the exact same, but > one has NA's in random locations. I thought instead of having the > second array as an integer, it could be logical and the TRUE vs FALSE > could be used to update data in the first array. (but even this idea > may be weak if I just end up with a third temporary array...) You probably would since any assignment is going to create a copy. And even having a bitwise logical option wouldn't necessarily help since the indexing would be of necessity either integer or logical (both 8 bit values). > > I'm running win xp sp3, "R version 2.14.1 (2011-12-22)". 31-bit addressing constraints as well? (That's so last decade.) You aren't making life easy for yourself are you. > -- David Winsemius, MD West Hartford, CT ______________________________________________ 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.
