I took a quick glance at the code and noted that it looks alot like similar VEC3 code I had written. I obtained large gains in execution speed by eliminating as many of the AREF commands as possible, using ELT instead.
I don't know why this worked, but even for multiple dimensional arrays I've found creating another DISPLACED-ARRAY of rank-1 (kinda like a pointer to an in C/FORTRAN) and using ELT is "much" faster than the use of AREF. mike
