Syntax:
set terminal tpic <pointsize> <linewidth> <interval>
where pointsize and linewidth are integers in milli-inches and interval is a float in inches. If a non-positive value is specified, the default is chosen: pointsize = 40, linewidth = 6, interval = 0.1.
All drivers for LaTeX offer a special way of controlling text positioning: If any text string begins with '{', you also need to include a '}' at the end of the text, and the whole text will be centered both horizontally and vertically by LaTeX. -- If the text string begins with '[', you need to continue it with: a position specification (up to two out of t,b,l,r), ']{', the text itself, and finally, '}'. The text itself may be anything LaTeX can typeset as an LR-box. 3#3rule{}{}'s may help for best positioning.
Examples:
About label positioning:
Use gnuplot defaults (mostly sensible, but sometimes not really best):
set title '\LaTeX\ -- $ \gamma $'
set label '{\LaTeX\ -- $ \gamma $}' at 0,0
set xlabel '[t]{\LaTeX\ -- $ \gamma $}'
set ylabel '[r]{\LaTeX\ -- $ \gamma $\rule{7mm}{0pt}}'