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POGenetic algorithm - Subset sum problem
 

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    <p>I have to do a project which using a genetic algorithm solves the subset sum problem. Unfortunately, when coding the algorithm I found a big problem ...</p> <p>My algorithm:</p> <ul> <li>as long as no solution was found and the number of steps is smaller than steps do:</li> <li>calculate the probability and then distribution function for each chromosome</li> <li>perform selection (roulette)</li> <li>select n chromosomes to be crossed</li> <li>perform the crossing (the crossing point is selected randomly)</li> <li>select m chromosomes to mutation</li> <li>perform mutations</li> <li>if you found a solution then stop</li> </ul> <p>(Algorithm was taken from the book "Genetic Algorithms + Data Structures = Evolution Programs, Chapter 2 ") Variables such as population size, amount of data, scope of data collection, number of steps, the number of mutations (in step), the number of crossings (in a step) is set rigidly in the program options.</p> <p>The problem is that after a certain (relatively small) number of steps in the population all the chromosomes are identical. The problem illustrates this graph: <a href="http://imageshack.us/m/96/7693/wykresb.png" rel="nofollow">http://imageshack.us/m/96/7693/wykresb.png</a></p> <p>What I'm doing wrong? How to fix it? Thanks in advance.</p> <p><strong>Edit:</strong></p> <p>Here You can find logs from my app: <a href="http://paste.pocoo.org/show/391318/" rel="nofollow">http://paste.pocoo.org/show/391318/</a></p> <p>I think that roulette is not the best solution (as deong said). Mutations also need to improve.</p>
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    1. COWhat language are you using to implement the algorithm? It sounds like an issue with the crossover and mutation phase. To troubleshoot turn off each of these phases and try and isolate the problem. I imagine it is something to do with the variables you are using and that you are not taking deep copies of chromosomes when applying these operators on your population..
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    2. COI think the issue may well be with your implementation, you would need to post your code.
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      1. USToby Allen
    3. CO@Gordon Murray Dent - I'm using Java. I will check this.
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