Hello,
using gnuplot 4.6.1 on linux i run the following commands:
set term wxt enhanced 1 font "Arial,10"
set xlabel 'Regular' font "Arial"
plot sin(x)
set term wxt enhanced 2
set xlabel 'Regular Large' font "Arial,20"
plot sin(x)
set term wxt enhanced 3
set xlabel 'Regular {/=20 Large}' font "Arial"
plot sin(x)
set term wxt enhanced 4 font "Arial,20"
fontsize = 20
set xlabel 'Regular Large' font "Arial"
plot sin(x)
No 1 and 4 are showing correct xlabels.
No 2 and 3 are cutting away half of the xlabel.
So the font size estimation seems to be incorrect here.
Is there anything wrong here?
The plot layout is done first using the font sizes given in the "set terminal" command. If you change the font size later for a particular element, in this case xlabel, then the space previously reserved for that element may be wrong.