[ANN] Watchmaker Framework for Evolutionary Algorithms version 0.3.0 released

Discussion in 'Java' started by Daniel Dyer, Dec 24, 2006.

  1. Daniel Dyer

    Daniel Dyer Guest

    Daniel Dyer, Dec 24, 2006
    #1
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  2. Re: Watchmaker Framework for Evolutionary Algorithms version 0.3.0 released

    Daniel Dyer wrote:
    > Project Home Page: https://watchmaker.dev.java.net/
    > Change Log: https://watchmaker.dev.java.net/CHANGELOG.txt
    > API Documentation: https://watchmaker.dev.java.net/nonav/api/index.html
    > Example Applet: https://watchmaker.dev.java.net/examples/salesman.html


    > Daniel Dyer
    > https://watchmaker.dev.java.net - Evolutionary Algorithm Framework for Java


    Well, it works, but without crossover, the TSP example
    is very weak. Without elitism it doesn't work very often
    at all.

    Do you have descriptions somewhere for your list of
    selection mechanisms? There are a couple I don't
    recognize.

    xanthian.
    Kent Paul Dolan, Dec 25, 2006
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  3. Daniel Dyer

    Daniel Dyer Guest

    Re: Watchmaker Framework for Evolutionary Algorithms version 0.3.0 released

    On Mon, 25 Dec 2006 22:55:17 -0000, Kent Paul Dolan <>
    wrote:

    > Well, it works, but without crossover, the TSP example
    > is very weak. Without elitism it doesn't work very often
    > at all.


    The TSP applet is not intended to be anywhere near as comprehensive as
    your own work on the problem. For example, my brute force implementation
    is very naive. It does serve two purposes though. Firstly as a
    demonstration of how to use the components in the framework to solve a
    problem and secondly as a demonstration of the effectiveness of
    evolutionary appoaches. You are probably right though, with cross-over it
    could be an even more effective demonstration of the power of evolution.
    It was something that I initially intended to include but, for whatever
    reason, I didn't. I may well add this in the next version and see what
    improvement I get.

    Did you implement ordered cross-over as defined on this page
    (http://www.permutationcity.co.uk/projects/mutants/tsp.html)?

    > Do you have descriptions somewhere for your list of
    > selection mechanisms? There are a couple I don't
    > recognize.


    I think they are all in the Mitchell book.

    Stochastic Universal Sampling is a fitness-proportionate strategy similar
    to Roulette Wheel Selection except that it ensures that observed selection
    frequencies are in line with expected frequencies. It is most useful for
    small populations where statistical anomalies could skew the results
    considerably if Roulette Wheel Selection was used.

    Rank Selection assigns selection probabilities as a function of the
    relative fitness scores rather than absolute scores. This can increase
    selection pressure when there is little variation in the population or
    reign it in when the fitness scores vary wildly. My default mapping
    function is very trivial (for a population of size n, the fittest
    candidate gets a score of n, the next n-1, etc. and selection is
    proportional to these scores). This default linear function can be
    over-ridden with something else (maybe in some situations it would be
    better for it to be exponential or logarithmic).

    Dan.

    (I have removed comp.lang.java.programmer from the follow-ups as this
    isn't really on-topic)

    --
    Daniel Dyer
    https://watchmaker.dev.java.net - Evolutionary Algorithm Framework for Java
    Daniel Dyer, Dec 26, 2006
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