16. gnuplot でグラフにする例
gnuplot> set datafile separator ","
gnuplot> set xdata time
gnuplot> set timefmt "%Y-%m-%d %H:%M:%S"
gnuplot> plot "logfile" using 1:2 w lp
gnuplot> set terminal png
gnuplot> set output 'temper.png'
gnuplot> plot "logfile" using 1:2 w lp