Author: Ralf Elvsén
Date: 03:33:00 07/02/00
Go up one level in this thread
On July 02, 2000 at 06:04:50, TEERAPONG TOVIRAT wrote: >>Yes, sure, you are right, and I think I do understand it quite well. >>I just wanted to say, that the resulting approximate formula for the >>error probability depends on N and H, and not on P (IMO). > >Thanks for your interest to my post. No one besides you seems to do so. >Perhaps it's too difficult for me to express the third factor (P/H ) in >detail(English). >Let me try. Do you notice N and H are relatively constant or controlled >by limitation of RAM ? In my hypothesis I base on assumption that every >hash value has approximately equal number of positions,but I think in >the actual situation is different. I don't know about the real distribution. >I know only a lot of people here say " not all random numbers are suitable >for hash value some of them leading to clash so often than others" . >So, the third factor should be the real number of positions that have the >same hash value not just by approximation. And now if my hypothesis >is correct. Will it be useful? As I said above we cannot control N,H. >I think we can detect a good series of random numbers by using these facts. >In last few days I spent hours in experiment about this. I test my checkers >program >with 32 bit hash table. The results are quite the same as I expect. >At the early stage of game the incidence of the type 1 error is so small. >As the number of positions occupied on the table increase the incidence >also increases until the table is fully occupied the incidence tend to be >stable at some constant. My current problem is my incidence of error is >higher than I expect. I got 0.5% instead of 1/4000. Do you think I can blame >it on my random integers? or Do you have any idea to generate a good series >of random number? >I'm sorry it's quite a long post. > >Thanks, >Teerapong Are you using "any" random numbers? When I experimented with a hash table I got a significant performance improvement when I used a collection of random numbers that were selected for their average mutual "Hamming distance" . There has been some discussion about this, but maybe you are aware of this already. Ralf that were
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.