changing font size

[Muyin Wang <muyin@xxxxxxxxxxxxx>]

Hello:
 Here is the question:
 When we do contour/shade plot, we can use the following combination to draw a
title for the plot:

contour/set/nolab x
ppl title @CR Title of contour-plot-x
ppl contour

But sometimes, the title appears too small, while other times the title is too
big, depending on the view setup. For a given view area, is there a way to
control the font size of "title"? If so, how could I do it? Thanks for the help!
Muyin