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Zobrist alternative?
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Don Dailey



Joined: 29 Apr 2008
Posts: 4496
PostPost subject: Re: Zobrist alternative?    Posted: Fri Jun 15, 2012 8:21 pm Reply to topic Reply with quote
Daniel Shawul wrote:
Quote:

hash = any_number;
hash = hash ^ cp;
hash = hash * FNV;
hash = hash ^ square;
hash = hash * FNV;

Well hash = ( any_number * FNV ) ^ sq only changes the lowest bits since it uses the _same_ number to initialize all squares.


I'm reading your post again and you are focused on just one step. The ^ sq only changes a few lower bits - but that's just ONE STEP. Even the best cryptographic hashes are complete crap without all the rounds and numerous mixing steps required. So I don't see why you are focused on that.
Quote:


It is similar to an sequentially executed LCG but poorer because in the latter case any_number is replaced by the previously generated random number. So what this method does is basically using sq as the hashkey. Note that the hash function is called every time the key for the piece on square is required, and it has to return the same key every time. So unless you store different initialization numbers (seeds) for each square (which again means storing it in a table), this can't work.
Quote:

I'm not explicitly mixing here but this will be pretty fast and avoid a lot of source code clutter with tables of random numbers.

The table could be generated at run time from a given seed so there is no need to store them in the source code. If same random numbers are required as in the case where the keys are used for book too, then the seed can be fixed. Also mixing will add a lot of code that is done twice..

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Subject Author Date/Time
Zobrist alternative? H.G.Muller Tue Jun 12, 2012 7:35 pm
      Re: Zobrist alternative? Kevin Hearn Tue Jun 12, 2012 7:44 pm
      Re: Zobrist alternative? Daniel Shawul Tue Jun 12, 2012 8:19 pm
            Re: Zobrist alternative? H.G.Muller Tue Jun 12, 2012 8:54 pm
                  Re: Zobrist alternative? Daniel Shawul Tue Jun 12, 2012 9:46 pm
                        Re: Zobrist alternative? Daniel Shawul Wed Jun 13, 2012 3:24 am
                        Re: Zobrist alternative? Daniel Shawul Wed Jun 13, 2012 4:14 am
                              ignored idea here Daniel Shawul Wed Jun 13, 2012 4:00 pm
                                    Re: ignored idea here Daniel Shawul Thu Jun 14, 2012 1:30 am
                                          Re: ignored idea here H.G.Muller Thu Jun 14, 2012 5:50 am
                                                Re: ignored idea here Daniel Shawul Thu Jun 14, 2012 12:52 pm
                                          Re: ignored idea here Edmund Moshammer Thu Jun 14, 2012 8:21 am
                                                Re: ignored idea here Edmund Moshammer Thu Jun 14, 2012 9:27 am
      Re: Zobrist alternative? Wylie Garvin Tue Jun 12, 2012 8:27 pm
            Re: Zobrist alternative? H.G.Muller Tue Jun 12, 2012 8:36 pm
                  Re: Zobrist alternative? Vincent Diepeveen Wed Jun 13, 2012 1:01 pm
                  Re: Zobrist alternative? Wylie Garvin Wed Jun 13, 2012 10:57 pm
                        Re: Zobrist alternative? H.G.Muller Thu Jun 14, 2012 5:42 am
                              Re: Zobrist alternative? Robert Hyatt Thu Jun 14, 2012 1:17 pm
                                    Re: Zobrist alternative? H.G.Muller Thu Jun 14, 2012 2:17 pm
                                          Re: Zobrist alternative? Wylie Garvin Thu Jun 14, 2012 6:11 pm
                        Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 10:05 am
      Re: Zobrist alternative? Reinhard Scharnagl Wed Jun 13, 2012 9:52 am
            Re: Zobrist alternative? Edmund Moshammer Wed Jun 13, 2012 9:58 am
                  Re: Zobrist alternative? Reinhard Scharnagl Wed Jun 13, 2012 12:49 pm
                        Re: Zobrist alternative? Edmund Moshammer Wed Jun 13, 2012 1:15 pm
                              Re: Zobrist alternative? Reinhard Scharnagl Wed Jun 13, 2012 1:41 pm
                                    Re: Zobrist alternative? Edmund Moshammer Wed Jun 13, 2012 3:55 pm
                                          Re: Zobrist alternative? Reinhard Scharnagl Wed Jun 13, 2012 4:03 pm
      Re: Zobrist alternative? H.G.Muller Wed Jun 13, 2012 2:19 pm
            Re: Zobrist alternative? Vincent Diepeveen Wed Jun 13, 2012 2:44 pm
            Re: Zobrist alternative? Vincent Diepeveen Wed Jun 13, 2012 2:48 pm
                  Re: Zobrist alternative? Vincent Diepeveen Wed Jun 13, 2012 3:28 pm
                  Re: Zobrist alternative? H.G.Muller Wed Jun 13, 2012 4:01 pm
                        Re: Zobrist alternative? Vincent Diepeveen Wed Jun 13, 2012 5:42 pm
                              Re: Zobrist alternative? H.G.Muller Wed Jun 13, 2012 5:51 pm
                        Re: Zobrist alternative? Vincent Diepeveen Wed Jun 13, 2012 6:27 pm
            Re: Zobrist alternative? Daniel Shawul Wed Jun 13, 2012 5:29 pm
            Re: Zobrist alternative? Karlo Bala Jr. Thu Jun 14, 2012 9:50 am
      Re: Zobrist alternative? Reinhard Scharnagl Thu Jun 14, 2012 8:49 am
            Re: Zobrist alternative? H.G.Muller Thu Jun 14, 2012 9:09 am
            Re: Zobrist alternative? Daniel Shawul Thu Jun 14, 2012 1:11 pm
                  Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 10:12 am
      Re: Zobrist alternative? Don Dailey Thu Jun 14, 2012 4:46 pm
            Re: Zobrist alternative? Don Dailey Thu Jun 14, 2012 6:38 pm
                  Re: Zobrist alternative? Daniel Shawul Thu Jun 14, 2012 6:57 pm
                        Re: Zobrist alternative? Don Dailey Fri Jun 15, 2012 2:39 pm
                              Re: Zobrist alternative? H.G.Muller Fri Jun 15, 2012 3:46 pm
                                    Re: Zobrist alternative? Daniel Shawul Fri Jun 15, 2012 5:22 pm
                                          Re: Zobrist alternative? H.G.Muller Fri Jun 15, 2012 5:38 pm
                                                Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 10:17 am
                              Re: Zobrist alternative? Daniel Shawul Fri Jun 15, 2012 5:04 pm
                                    Re: Zobrist alternative? Don Dailey Fri Jun 15, 2012 6:00 pm
                                          Re: Zobrist alternative? Daniel Shawul Fri Jun 15, 2012 7:27 pm
                                                Re: Zobrist alternative? Don Dailey Fri Jun 15, 2012 8:16 pm
                                                      Re: Zobrist alternative? Daniel Shawul Fri Jun 15, 2012 8:42 pm
                                                      Re: Zobrist alternative? Daniel Shawul Fri Jun 15, 2012 9:14 pm
                                                            Re: Zobrist alternative? Don Dailey Fri Jun 15, 2012 10:59 pm
                                                                  Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 12:17 am
                                                                        Re: Zobrist alternative? Don Dailey Sat Jun 16, 2012 4:28 am
                                                                              Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 6:30 am
                                                                                    Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 10:09 am
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 10:22 am
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 10:42 am
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 10:54 am
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 11:03 am
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 11:08 am
                                                                                          Re: Zobrist alternative? Don Dailey Sat Jun 16, 2012 12:03 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 12:55 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 2:21 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 2:25 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 2:44 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 12:35 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 1:11 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 1:15 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 1:56 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 2:05 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 2:10 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 2:22 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 2:29 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 2:35 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 2:39 pm
                                                                                          Re: Zobrist alternative? Don Dailey Sat Jun 16, 2012 3:49 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 4:35 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 2:11 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 2:13 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 2:19 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 2:29 pm
                                                                                          Re: Zobrist alternative? Vincent Diepeveen Sat Jun 16, 2012 2:32 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 4:19 pm
                                                                                          Re: Zobrist alternative? Don Dailey Sat Jun 16, 2012 4:50 pm
                                                                                          Re: Zobrist alternative? Daniel Shawul Sat Jun 16, 2012 4:25 pm
                                                Re: Zobrist alternative? Don Dailey Fri Jun 15, 2012 8:21 pm
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