On Jan 3, 2006, at 2:26 PM, Prof Brian Ripley wrote: > On Tue, 3 Jan 2006, Kasper Daniel Hansen wrote: > >> On Jan 3, 2006, at 9:36 AM, Brian D Ripley wrote: >> >>> I use save.image() or save(), which seem exactly what you are >>> asking for. >> >> I have the (perhaps unsupported) impression that Ross wanted to >> save the progress during the optim run. Since it spends most of >> its time in the .Internal(optim(***)) call, save/save.image would >> not work. > > It certainly does not! It is most likely spending time in the > callbacks to evaluate the function/gradient. We have used save() > to save the current information (e.g. current parameter values) > from inside optim so a restart could be done, but then I have only > once encountered someone running a single optimization for over a > week: there normally are ways to speed things up.
I stand corrected. Actually I should have thought of this. . /Kasper >> /Kasper >> >>> On Mon, 2 Jan 2006, Ross Boylan wrote: >>>> I would like to checkpoint some of my calculations in R, >>>> specifically >>>> those using optim. As far as I can tell, R doesn't have this >>>> facility, >>>> and there seems to have been little discussion of it. >>>> checkpointing is saving enough of the current state so that work >>>> can >>>> resume where things were left off if, to take my own example, >>>> the system >>>> crashes after 8 days of calculation. >>>> My thought is that this could be added as an option to optim as >>>> one of >>>> the control parameters. >>>> I thought I'd check here to see if anyone is aware of any work >>>> in this >>>> area or has any thoughts about how to proceed. In particular, >>>> is save a >>>> reasonable way to save a few variables to disk? I could also >>>> make the >>>> code available when/if I get it working. >>> -- >>> 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 >>> ______________________________________________ >>> R-devel@r-project.org mailing list >>> https://stat.ethz.ch/mailman/listinfo/r-devel >> >> > > -- > 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 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
