I recently ran a script which fit many different models (thousands, say) via glm(), some of which were successful and some not. For the unsuccessful fits, I caught them using tryCatch() and returned either a "simpleError" object or a "simpleWarning" object, depending on whether it was an error or a warning that triggered the tryCatch. I stored all the results in a single big list and I was surprised to see that the memory usage was nearly a 1 GB, but calling object.size() on the results list only returned about 5 MB (I only store two numbers from each fitted model object). When I saved the results list the compressed workspace file was ~90MB. The only thing I'd done differently from previous runs is store the error/warning objects. Is there some environment that is being saved with a simpleError/Warning object that could be taking up all the memory? I couldn't find any indication on the help page for tryCatch(). Thanks, -roger -- Roger D. Peng http://www.biostat.jhsph.edu/~rpeng/