"Stuart Leask" <[EMAIL PROTECTED]> writes: > > One concern I recall from looking into this a while back (hopefully > > not founded) was the issue with floating point handling on the ARMs > > and similar PDA CPUs. > > > > This was relevant to the familiar/intimate linux distro's around 18-24 > > months ago, when I was considering an IPAQ or Zaurus to replace my old > > but not dead yet palm. > > Thanks to the excellent work of the R developers in keeping all the code > quite standard, and some specific work by Simon Pickering (Bath University), > I have had R working (with graphics) on my Sharp Zaurus for some time. > Sadly, checking today his site is down, but binaries for the Zaurus are > available. > > There was a problem with NA handling that needed specifically addressing, > and some missing fonts, but the fpu emulation worked fine. This was using > X11, keypebble and VNC. It could _just about_ run in the standard RAM - > although was a lot happier with extra memory. Most impressive, and well done > Simon (and the R team).
Right. As I recall it, the FPU/NA issue was a case of configure getting the byte-order wrong and not (as was believed for a while) a problem with non-IEEE arithmetic. > However, a note of caution - presumably due to the lack of a hardware fpu, > and perhaps also the relatively slow access speed of SD ram, benchmarks on > the zaurus ran anything up to (wait for it!) 100 times slower than a pentium > of the same clock speed. This has sadly left R on my Zaurus largely idle, as > in practice I found it just too slow to be usable. Hmm. So you're probably limited to problems that require on the order of tens of milliseconds FPU time on a normal machine. I suppose that there are usages where this is feasible. > I fear this problem could afflict any handheld implementation, until they > start putting fpu's on these chips. Yes. Now where are the video gamers when you need them? > (PS. I have the same problem with a mini-ITX 'silent PC' - many of these > low-power cpus (eg. Eden) lack hardware FPU. They run many office apps fine, > but when I benchmarked with a stats program, I found it 50 times slower than > a pentium of equivalent clock speed! I am advised that even those that do > have hardware FPU eg. the Nehemiah chip are only 50-60% as fast as a > pentium-class cpu of similar clock speed) Hmm, the newer ones (Eden-N, Eden-ESP) claim "full-speed FPU". I've been toying around with the idea of building a system around the MythTV stuff to get a harddisk video recording, etc. Could be kind of fun to run R on it with display to the TV (but could you control R with the TV remote control?) -- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
