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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>I am currently using CppBugs with Rcpp through R. I am very interested to use CppBugs as I am finding WinBugs to be prohibitively slow, I use large amounts of data in large multilevel models, so when I found cppbugs I was excited. It says on the Github page for cppbugs that I can achieve speeds of 20-100x faster than winbugs.<o:p></o:p></p><p class=MsoNormal>I have been testing some examples: for the linear model example that is provided at Github, the time difference is about 2x<o:p></o:p></p><p class=MsoNormal>I also tested the Radon model with Rcpp and Andrew Gelmans data and for 10000 iterations and 10000 burnin with a thinning parameter of 5 the difference is only 16 seconds vs 13 seconds.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I can run multiple chains in parallel through R with the ‘snow’ package, cxxfunction() and package.skeleton() and this does seem to provide a little bit of a boost (parallel winbugs vs parallel cppbugs). But nothing greater than 4x.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Is it possible to achieve the kind of difference mentioned on Whit Armstrong’s page for cppbugs with R?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I am happy to post all the code if required.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Many thanks<o:p></o:p></p><p class=MsoNormal>Sam Watson<o:p></o:p></p></div></body></html>