set terminal postscript eps color solid 20 set xlabel "time (2 hour interval)" set xtic 2 set xrange [-1:23] set yrange [0:] set key top left set ylabel "Traffic (Mbps)" plot "hourly_out.txt" using 1:($3/1000000) title 'mean' with lines, \ "hourly_out.txt" using 1:($3/1000000):($4/1000000) title "stddev" with yerrorbars