# set terminal svg size 600,400 dynamic enhanced fname 'arial'  fsize 10 mousing name "pointsize_2" butt solid 
# set output 'pointsize.2.svg'
unset border
unset key
set view map
set style data lines
set noxtics
set noytics
set noztics
set title "splot with variable size points\nit is possible to specify size and color separately" 
x = 0.0
splot 'world.dat' using 1:2:(0) with lines lt 3,       'world.cor' using 1:2:(0.5-rand(0)):(5.*rand(0)) with points pt 5 ps var lt palette