set output "times-b.ps"
set terminal postscript
set xlabel "runs"
set ylabel "seconds"
plot [0:] [0:]         'times-b.log' using 2 title 'ISAM-b(real)' with linespoints,         'times-b.log' using 3 title 'ISAM-b(user)' with linespoints,         'times-b.log' using 4 title 'ISAM-b(sys)' with linespoints