Forums before death by AOL, social media and spammers... "We can't have nice things"
|    comp.ai    |    Awaiting the gospel from Sarah Connor    |    1,954 messages    |
[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]
|    Message 284 of 1,954    |
|    the 'dude' to All    |
|    HELP: Population size, Mutation rate    |
|    05 Apr 04 14:54:23    |
      From: pdenboef@hotmail.com              I am using a RCGA with a HUGE search space. I need to extract a set of rules       (say 15-30 rules) from very complex data containing 24 attributes. The       complex data is gathered from a well-trained ANN, which I wish to use in       order to study knowledge representation/ rule extraction.              Each antecedent has roughly 10 possibilities, which was reduced using an       attribute selection and discretization algorithm--Chi2. Classification       clustering has reduced the two dimensional classification space to 13       possibilities. Clearly my search space is still very big! I have had some       success with population sizes of 5000.... but I tend to get stuck in local       minimums a lot. Computational cost is huge! I have been looking into       optimizing my population size and mutation rate. I have been playing with       pop sizes of 1000-5000 and mutation rates of 0.01. My mutation operator       randomly changes only one gene.              Right now I don't know what I should do.....experiment with larger mutation       rates to keep diversity and prevent premature convergence into local       minimums..... I have heard that small populations with larger mutation rates       can be more efficient than larger populations with smaller mutation rates.       Shit- I worry that my endeavor is not feasible and that my search space is       too damn big.              Please help!!!!!!!              the 'dude'              [ comp.ai is moderated. To submit, just post and be patient, or if ]       [ that fails mail your article to |
[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]
(c) 1994, bbs@darkrealms.ca