Author: John Merlino
Date: 11:41:51 12/06/00
Go up one level in this thread
On December 05, 2000 at 15:26:12, Jason Williamson wrote: >On December 04, 2000 at 19:17:21, John Merlino wrote: > >>On December 04, 2000 at 15:30:34, Jason Williamson wrote: >> >>>On December 03, 2000 at 14:55:01, John Merlino wrote: >>> >>>>On December 03, 2000 at 11:23:19, David Dahlem wrote: >>>> >>>>> >>>>>On December 02, 2000 at 21:09:58, John Merlino wrote: >>>>> >>>>>>On December 02, 2000 at 18:23:02, David Dahlem wrote: >>>>>> >>>>>>>I have been trying to create an opening book by importing a pgn file. Every >>>>>>>attempt has resulted in this message - "import error: an error occurred >>>>>>>importing the pgn file". Has anyone else tried to import pgn files into an >>>>>>>opening book in CM8000? Does the pgn file have to be free of commentary and/or >>>>>>>variations? >>>>>>> >>>>>>>Dave >>>>>> >>>>>>If you think the PGN file is completely free of errors, then E-mail me the file >>>>>>and I'll pass it on to the development team. Does the error message give you any >>>>>>indication of WHERE in the file the error occurred, or WHAT the error is? >>>>>> >>>>>>jm >>>>> >>>>>I decided to try a little test. I thought maybe the problem was with the size of >>>>>the pgn file so i created some with only 100 games. These were imported without >>>>>an error message. Then i tried a pgn file with 500 games and got the error >>>>>message. So it appears the problem with CM8000 importing pgn files into the >>>>>opening book is with file size. Unless someone wanted to take a large amount of >>>>>time splitting a large pgn file into very small ones, the import pgn into CM8000 >>>>>opening book is worthless, unless this is addressed in the patch. >>>>> >>>>>Dave >>>> >>>>It is possible that the number of games is the problem, but I know for a fact >>>>that I have used it to import PGN files with more than 3,000 games. However, the >>>>one factor is HOW MANY DIFFERENT OPENINGS are in the PGN file. The more >>>>disparate the openings, the bigger the opening book will be, and the opening >>>>book format can only handle a certain number of moves. Since the default depth >>>>is either 30 or 40 plies (can't remember), this could cause a problem. In other >>>>words, you can import more games if the games all use the same family of >>>>openings. >>>> >>>>I do know that the patch is going to address this SOMEWHAT by giving the user >>>>many importing options, such as the depth of the book, what criteria to set the >>>>frequency of the moves, etc. Hopefully, this will "solve" the problem. >>>> >>>>jm >>> >>>Oh, are you telling me that the opening book creator is limited in the number of >>>lines that it can use? Thats pretty sad. I wanted to create a massive opening >>>book from my large pgn. Yace uses an opening book that is built from a 600 meg >>>PGN file. Crafty uses an opening book built from a 1.2 GIG pgn. In both those >>>cases though they use extensive pruning of the moves out, and do not store the >>>whole game of course. >>> >>>JW >> >>Actually, the limit is the number of MOVES (or nodes), not LINES, but the result >>is still the same. I believe the maximum number of moves/nodes is about 64K, or >>around 65,000. Therefore, assuming the default depth for the opening book >>importer is 40 plies (although it might be 30), if the games in the PGN file are >>different enough in their openings, then you will only be able to import around >>1,500 games. >> >>This is a worst case scenario, however, and I have found that I am able to >>import closer to 3,000 games with only the occasional overflow error message. I >>admit that this is not like being able to import a HUGE PGN file as you mention >>in those other programs, but the problem stems from the fact that Chessmaster's >>opening book format has not changed since Chessmaster 5000. >> >>I can tell you, though, that the patch is going to provide the user with some >>ability to set the parameters in which a PGN file is imported, one of them being >>depth. So, obviously, with a depth of only 15-20, in the worst case you will be >>able to import twice as many games (in practice, though, probably at least four >>times as many). >> >>jm >> >> >>jm > >Why have this limit at all? Large opening books do not scare me, heck all my >chessbase engines have 300+ meg books. Is this limit imposed because of an >assumption that users don't want to have disk space consumed by a large book? >In the day of CM5k, this might have been more true, but hard drive space is >cheap now, and lots of people have 40+ gigs. My chess software takes up a mere >10-15 gigs of hd space :) > >JW This limit basically exists because of legacy code. The source for creating many of the opening books in the game has been lost (since some of the books are over 5 years old) and so the development team is somewhat reluctant to change the format. This is likely to occur in the next version of Chessmaster, however. jm
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