Syntax:
set terminal rgip | uniplex {portrait | landscape} {[<horiz>,<vert>]} {<fontsize>}
permissible values for the font size are in the range 1-8, with the default being 1. The default layout is landscape. Graphs are placed on the page in a horizxvert grid, which defaults to [1,1].
Example:
set terminal uniplex portrait [2,3]
puts six graphs on a page in three rows of two in portrait orientation.