Joe: all matrices are 100 x 1000, what I assumed was reasonable. In the past, when I was using matlab, I used to mesh matrices of size 200 x 2000 on a P4 with 1 Gb RAM, and it always displayed in less than a minute. That's why I assume that meshing 100 x 1000 matrices should be no big deal (at least, in terms of hardware). Anyway, I am trying to mesh 10 x 100 matrices in this current setup (PPC G5, 2 Gb RAM +
octave-2.1.73), and I am getting very slow plotting.
Dmitri: I tried your suggestion (only that the __gnuplot_raw__ lines are in meshc.m, not mesh.m), but they did not help, while I used AquaTerm. setting GNUTERM=x11 (and following your suggestion), the plots displayed almost immediately. Thanks very much.
After this little experimentation, I tend to think it's some problem with AquaTerm. If anyone can think of some way to tweak AquaTerm to yield faster #d plots, I will be very thankful, as plots done using AquaTerm are much prettier (and I can interactively export to PDF).