  input "Cache hit ratio (0-1)? " h
  input "Disk I/O time in seconds? " d
  input "Time to write to cache? " c
! input "Ratio of writes to sum of reads and writes? " w
  print "write ratio","writeintocache","writethrucache","ratio"
  for w=0 to 1 step .1
      writethrucachetime=(h*c+(1-h)*d)*(1-w)+w*(c+d)
      writeintocachetime=(h*c+(1-h)*d)*(1-w)+w*c
      print w,writeintocachetime,writethrucachetime,...
&           writeintocachetime/writethrucachetime
   next w
end
