Format plot axis

[Qualitang]

Hi,

I'm trying to make the units on the axis of a plot bigger. Also, when
I print a plot the size of the axis label font is different from that
shown in gplot.

I'm printing the plot to a .jpeg and I get this when I try to set the
font as Times-Roman:

gdImageStringFT: Could not find/open font while printing string y kpc
with font Times-Roman

Any help appreciated!

thanks,
M.