[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Bug-gnubg] Bearoff database
From: |
Philippe Michel |
Subject: |
Re: [Bug-gnubg] Bearoff database |
Date: |
Thu, 12 Jan 2017 07:52:13 +0100 (CET) |
User-agent: |
Alpine 2.20 (BSF 67 2015-01-07) |
On Thu, 12 Jan 2017, Øystein Schønning-Johansen wrote:
Really strange!
I have built a one sided database using GMP with fractions with my own
piece of code. Since I use fractions from GMP there should be no rounding
error. Here are my numbers for position index 47:
Index: 47
0: 0
1: 0
2: 1/18
3: 445/648
4: 5939/23328
5: 73/23328
These numbers agrees to the numbers GNU Backgammon. Can it really play this
incorrectly? How does that happen?
I now think GNU gets it right. By default race4 reads a race4.hash file
where it stored the results of prior uses. Mine was apparently somehow
corrupted. Starting with the lingering hash file present, I get :
% race4 1 0 0 0 1 1
initial hash stats: entries 15227 overwrites 0
Eval <12 | 1 0 0 0 1 1 | >...
Expected number of rolls = 2.117155; sigma = 0.575819
hash stats: queries: 1 hits 1 entries 15227 overwrites 0
Starting from scratch :
% race4 -i /dev/null -o /dev/null 1 0 0 0 1 1
initial hash stats: entries 0 overwrites 0
Eval <12 | 1 0 0 0 1 1 | >...
.....................
Expected number of rolls = 2.205290; sigma = 0.529637
hash stats: queries: 1565 hits 1526 entries 39 overwrites 0