gnuplot -e "set terminal pdf color; rng='::0::2'" advertisement.gp >/tmp/advertisement-ohne-hcg-color.pdf
gnuplot -e "set terminal pdf monochrome; rng='::0::2'" advertisement.gp >/tmp/advertisement-ohne-hcg-monochrome.pdf
gnuplot -e "set terminal pdf color; rng='::3::6'" advertisement.gp >/tmp/advertisement-mit-hcg-color.pdf
gnuplot -e "set terminal pdf monochrome; rng='::3::6'" advertisement.gp >/tmp/advertisement-mit-hcg-monochrome.pdf