# set terminal pngcairo  font "arial,8" size 500, 300 
# set output 'circles.4.png'
unset key
set size ratio -1 1,1
set title "Delaunay triangulation of Hemisphere points, some empty circles in red" 
set rrange [ * : * ] noreverse nowriteback  # (currently [8.98847e+307:-8.98847e+307] )
set trange [ * : * ] noreverse nowriteback  # (currently [-5.00000:5.00000] )
set xrange [ * : * ] noreverse nowriteback  # (currently [-100.000:100.000] )
set x2range [ * : * ] noreverse nowriteback  # (currently [-97.9983:96.4970] )
set yrange [ * : * ] noreverse nowriteback  # (currently [-100.000:100.000] )
set y2range [ * : * ] noreverse nowriteback  # (currently [-96.8269:95.3829] )
plot 'empty-circles.dat' with circles lw 2 lc rgb "red",      'delaunay-edges.dat' with lines lc rgb "forest-green",      'hemisphr.dat' u (100*$1):(100*$2) with points pt 7 lc rgb "black"