An embedded and charset-unspecified text was scrubbed... Name: not available URL: <https://stat.ethz.ch/pipermail/r-sig-mixed-models/attachments/20110804/39bbfbdc/attachment.pl>
MCMCglmm computation time
2 messages · Stephane Chantepie, Jarrod Hadfield
9 days later
Dear Stephane, I should probably allow the option of writing-to-file during an MCMC run for those with temperamental power supplies .... You can merge MCMC chains from multiple runs, although you should make sure you start them from different initial values and that they pass convergence diagnostics. mcmc.list from the library coda is useful for manipulating parallel chains. Cheers, Jarrod
On 4 Aug 2011, at 14:14, Stephane Chantepie wrote:
Dear all, I am a phd candidate working on aging in some bird species. To achieve this, I have started to use MCMCglmm a few month ago. To detect senescence, I need using large data sets and hence I have to wait about two weeks or often more for the runs to complete. My major problem is that the capricious electricity network often shut down my computers, so I am looking for ideas to reduce computation time (and finish runs). I have read on the internet that it is too complicated (or impossible) to gain time on the algorithm. So, I have decided to use the package "doMC" in order to divide the markov chain between the cores of my computers. With this, instead of running a model with 4300000 iterations (with 300000 burning iterations), I would run in parallel four models (one by core) with 1300000 iterations (300000 burning iterations and the same prior in the 4 models). My question : Is it possible to concatenate results after burning (Sol, VCV, deviance) and use it like a single big model or is it conceptually wrong? I know that I loose computation time by multiplying burning but is it wrong to do this alternative strategy? Thanks a lot in advance for your input, Best Stephane -- Stephane Chantepie CNRS Phd candidate Mus?um national d'Histoire naturelle 55 rue Buffon 75005 paris Tel : 01 40 79 32 03 E-mail : chantepie at mnhn.fr -- [[alternative HTML version deleted]]
_______________________________________________ R-sig-mixed-models at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.