I said Latex called the “lower case omega with ~ on top” \varomega. A little hunting found that TLatex does that, but TeX calls it \varpi. And I should have mentioned that another problem with PGplot and LaTeX is that the former likes to draw Postscript plots ( .ps for Linux users) but the latter wants them to be either .ps or .pdf but not both in the same document, and some publishers are fussy about wanting .eps instead.