fontenot@rice.edu (Dwayne Jacques Fontenot) (01/29/91)
Hello, Does anyone know where I can get some source or a pseudo-code algorithm for Bill Gosper's "Hashlife"? The information I have says that the hashlife algorithm was designed in 1982 and that it uses self-referential hash tables to store lookup patterns for John Conway's game of life. The algorithm is somewhat adaptive in that it "learns" which patterns to store and works up from relatively small patterns (4 x 4) to arbitrarily large ones. As you might deduce from the above, the algorithm starts out slowly and then accelerates logarithmically. I deduce that it uses memory in the same way ;-) The algorithm has the intriguing property of storing, in the hash table, all the information to recreate the life universe at any time in its history. Gosper was described as running backwards and forwards in time to see how interesting forms were produced. The description I saw (in the book, Mind Children) was not complete enough (in my opinion, anyway) for me to implement the alogorithm. I would like to implement this algorithm, but I believe I need a better description than was given in the book. Source code of any kind would be even better... Thank you for your time, Dwayne Fontenot fontenot@uncle-bens.rice.edu
ACW@YUKON.SCRC.Symbolics.COM (Allan C. Wechsler) (02/23/91)
Date: Mon, 28 Jan 1991 15:35 EST From: fontenot@rice.edu (Dwayne Jacques Fontenot) Hello, Does anyone know where I can get some source or a pseudo-code algorithm for Bill Gosper's "Hashlife"? The information I have says that the hashlife algorithm was designed in 1982 and that it uses self-referential hash tables to store lookup patterns for John Conway's game of life. The algorithm is somewhat adaptive in that it "learns" which patterns to store and works up from relatively small patterns (4 x 4) to arbitrarily large ones. As you might deduce from the above, the algorithm starts out slowly and then accelerates logarithmically. I deduce that it uses memory in the same way ;-) The algorithm has the intriguing property of storing, in the hash table, all the information to recreate the life universe at any time in its history. Gosper was described as running backwards and forwards in time to see how interesting forms were produced. The description I saw (in the book, Mind Children) was not complete enough (in my opinion, anyway) for me to implement the alogorithm. I would like to implement this algorithm, but I believe I need a better description than was given in the book. Source code of any kind would be even better... Thank you for your time, Dwayne Fontenot fontenot@uncle-bens.rice.edu I am forwarding your message to Gosper in case he hasn't seen the request.