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POHow to store sets, to find similar patterns fast?
 

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  1. POHow to store sets, to find similar patterns fast?
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    <p>(This is no homework and no work issue. It's just my personal interest/occupation and completly fictional. But I am interested in a good algorithm or data structure.)</p> <p>Let's assume, that I would run a dating site. And my <strong><em>special feature</em></strong> would be that the singles were <strong>matched by movie taste</strong>. (Why not?)</p> <p>In that case I would need a way to store the movie ratings for each user. (So far no problem.) And I would need a data structure to find the best fitting user. The distance between two taste patterns would be the average distance between all ratings that both users made.</p> <p><strong>Example</strong></p> <pre><code>movies A B C D E F G H I J K L M ... user Xm 9 5 1 1 5 user Ym 4 6 1 8 user Zf 9 6 4 7 </code></pre> <p>Distance(X,Z) = avg( abs(9-9) + abs(1-4) ) = 1.5</p> <p>Distance(Y,Z) = avg( abs(4-6) + abs(6-4) + abs(8-7) ) = 1.666</p> <p>So Mr. X fits slightly better to Mrs. Z, than Mr. Y does. </p> <p><strong>I like soulution that ...</strong></p> <ul> <li>... don't need many operations on the database</li> <li>... don't need to handle a lot of data</li> <li>... run fast</li> <li>... deliver the best matching</li> <li>Ok, maybe I would consider good approximations too.</li> </ul> <p>Try to keep in mind that this should also work with thousands of possible movies, users that rate only about 20-50 movies, and thousands of users.</p> <p>(Because this is a mental puzzle and not a real problem, work-arrounds are not really helping.)</p> <p><strong>What would be your search algorithm or data structure?</strong></p>
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    1. USMrFox
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    1. COIf I may ask … why L1? This doesn't sound particularly well suited.
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      1. USKonrad Rudolph
 

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