http://issues.apache.org/SpamAssassin/show_bug.cgi?id=2427
------- Additional Comments From [EMAIL PROTECTED] 2007-01-05 06:34 ------- btw there's an interesting set of code in "masses/evolve_metarule" in SVN which seems to do something related... here's the README: Genetic Algorithm Optimizer for Meta Rules Henry Stern Anti-Spam Engineering McAfee International Alton House Gatehouse Way Aylesbury, Bucks HP19 8YD April 9, 2005 1. WHAT IS IT? This program is used to optimize phrase-based meta rules such as ADVANCE_FEE and NIGERIAN for performance by selecting a subset of the candidate body rules. It selects rule sets based on combined hit rates, false positive rates and a desired number of rules. This program requres the GAUL: Genetic Algorithm Utility Library which can be obtained from http://gaul.sourceforge.net/. It is licensed under the GPL. 2. OPTIONS Config parameters: -h hits_file Path to the compressed matrix containing the rule hits. Default: hits.dat -r rules_fule Path to the file containing the rule names corresponding to columns in the compressed matrix. Default: rules.dat Fitness function parameters: -m maximum_relevant_hits Stop counting hits after seeing this many. The rule analogue of this is: ADVANCE_FEE_1, ADVANCE_FEE_2, ..., ADVANCE_FEE_m Default: 4 -t target_num_rules How many sub-rules should be used by the meta rule. Default: 50 -l target_flex_rules Solutions with target_num_rules +/- target_flex_rules are half as fit as solutions with target_num_rules. Default: 5 -e hits_exponent Parameter to the fitness function, how the importance of high numbers of hits is. Default: 3.0 -p penalty_exponent If rules hit ham, this exponential penalty is applied based on the number of hits. Default: 9.0 GA parameters: -s population_size How many individuals should be used in the simulation. Default: 100 -g max_generations How many geenrations that the simulation should run for. Default: 10000 -x crossover_prob The probability of an allele-mixing cross-over. Default: 1.0 -u mutation_prob The probability of a one-allele mutation. Default: 0.1 3. HOW DOES IT WORK? For every generation, "Parents" are selected based on their fitness. Parents are "mated" to produce two children. The alleles on each chromosome are randomly selected, which isn't very biologically plausible, but it works. Fitness of an individual is evaluated based on hit rates, false positive rates and how close the individual is to the target number of rules. -- hs 9/5/2005 ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee.
