# set terminal pngcairo  background "#ffffff" enhanced fontscale 2.5 size 500, 500 
# set output 'cities.1.png'
unset border
unset key
set encoding utf8
set datafile separator "	"
set size ratio 1 1,1
set noxtics
set noytics
Scale(size) = 0.25*sqrt(sqrt(column(size)))
CityName(String,Size) = sprintf("{/=%d %s}", Scale(Size), stringcolumn(String))
GPFUN_Scale = "Scale(size) = 0.25*sqrt(sqrt(column(size)))"
GPFUN_CityName = "CityName(String,Size) = sprintf(\"{/=%d %s}\", Scale(Size), stringcolumn(String))"
plot 'cities.dat' using 5:4:($3 < 5000 ? "-" : CityName(1,3)) with labels