1 set terminal postscript eps
2 set output "bench1.eps"
5 plot "1000x1000.dat" title "isam 1000" with linespoints, \
6 "100x10000.dat" title "isam 100" with linespoints, \
7 "10x100000.dat" title "isam 10" with linespoints, \
8 "1x1000000.dat" title "isam 1" with linespoints