In the meantime, I've been using 3dLME (with my old AFNI binaries folder) for the analysis I would eventually like to run in 3dMVM. It is quite a large dataset - 1 between subject variable (3 groups, n = 16, 16, 28), and 3 within-subject task variables (each with two levels). I've been getting the following error message when I try to run an omnibus analysis with 3dLME:

R(19088,0xac6e5a28) malloc: *** mmap(size=663556096) failed (error code=12)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug
R(19088,0xac6e5a28) malloc: *** mmap(size=663556096) failed (error code=12)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug
Error: cannot allocate vector of size 632.8 Mb
Execution halted

I've read that 3dMVM is also computationally expensive so I expect I might run into a similar problem when I get that program up and running. Is this a memory limitation at the level of R or 3dLME (and is there anything I can do about it?), or does this mean I need to upgrade to a more powerful machine or rethink my analysis?

Thanks for all the help!

L