# set terminal pngcairo  transparent enhanced font "arial,10" fontscale 1.0 size 500, 350 
# set output 'world.4.png'
set dummy u,v
set angles degrees
unset key
set parametric
set view 70, 40, 0.8, 1.2
set samples 32, 32
set isosamples 13, 13
set mapping cylindrical
set hidden3d back offset 0 trianglepattern 3 undefined 1 altdiagonal bentover
set yzeroaxis linetype 0 linewidth 1.000
set ticslevel 0
set title "3D version using cylindrical coordinate system" 
set urange [ -180.000 : 180.000 ] noreverse nowriteback
set vrange [ -90.0000 : 90.0000 ] noreverse nowriteback
splot cos(u),sin(u),v with lines lc rgb "cyan" ,'world.dat' with lines lc rgb "blue" lw 2, 'world.cor' with points lt 1 pt 2