Hello, I'm running up against similar problems as described previously: https://stat.ethz.ch/pipermail/r-help/2011-October/292897.html I've tried to set threshold=0.99, however, I got another error message: "Error: cannot allocate vector of size 52.8 Gb" I tried to run my code on a supercomputer with 100GB memory, however, I got another error message: "Error: cannot allocate vector of size 127.8 Gb" So, I guess that it might not be a real problem with memory size. Does anyone know what's wrong? Thanks! Cathy [[alternative HTML version deleted]]