tag:blogger.com,1999:blog-73593477114497230552023-11-15T17:41:53.048+01:00My approach to Netflix PrizeWojtek Kulikhttp://www.blogger.com/profile/09788309657571259554noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-7359347711449723055.post-21428939243071253822009-09-20T10:45:00.004+02:002009-09-20T10:51:00.470+02:00My method revealedI decided to reveal my method of predicting ratings in very short time.<br />Details can be found <a href="http://sites.google.com/site/wojtekkulik/">here</a>.<br />This stuff is commentware :-)<br /><br />Enjoy!Wojtek Kulikhttp://www.blogger.com/profile/09788309657571259554noreply@blogger.com3tag:blogger.com,1999:blog-7359347711449723055.post-17512215855353604572009-07-22T12:33:00.003+02:002009-07-24T18:56:50.508+02:00Fast algorithm v2Here's another one: 0.8840 in 8 minutes. Machine spec as before.<br /><br />I'm quite sure this approach would lead to much better solution, maybe even 0.8560 :-) I wish I had more time (3! months would be enough) or - at least - 12! times faster machine...Wojtek Kulikhttp://www.blogger.com/profile/09788309657571259554noreply@blogger.com3tag:blogger.com,1999:blog-7359347711449723055.post-84668539617398473492009-02-11T13:33:00.003+01:002009-02-11T16:56:40.529+01:00Fast algorithmFast CF algorithms have a future, as I don't think that blending hundreds (or even dozens) of predictors is acceptable in real recommender system.<br />Unfortunately, most of published algorithms tried in this contest needs hours of computations to produce a decent result.<br /><br />I've been recently working on my "fast" algorithm; the goal was to develop an algorithm with lowest RMSE and running time not exceeding 10 minutes.<br />Now it's time I may proudly announce the result: my algorithm can produce a 0.8927 QRMSE solution in seven (7) minutes (including reading raw data and writing result file) on my AMD 64 X2 Dual Core @5200+ machine, without using parralelism of any kind (like CUDA, OpenMP, etc.). It's not a totally new algorithm, but rather a clever modification of what was already published by one of the leading teams.<br /><br />If anyone has an algorithm which offers a better solution in similar time, please let me know.Wojtek Kulikhttp://www.blogger.com/profile/09788309657571259554noreply@blogger.com5tag:blogger.com,1999:blog-7359347711449723055.post-19933469522834578412009-01-21T10:06:00.002+01:002009-01-21T10:28:13.244+01:00More gigabytes on boardMy machine has 8GB of RAM now. I could still work with 4GB, but - you know - memory got so cheap these days... It's not worth using error-prone data & structure packaging any longer (I mean more error-prone than cf algorithms themselves). Not to mention that this challenge is not the only thing I'm currently working on.<br />There's bad news though: my motherboard won't accept more RAM, so the next step would be to replace the whole mobo ;-)<br /><br />I still remember buying additional RAM for my first PC machine: it was in mid-1990's, I was doubling my machine's 4MB (some silly game required 8MB). BTW: Windows 95 worked really nice with 4MB, as far as I remember.<br />Both me and my machine(s) have changed a lot since then...<br /><br />Let's find out if more RAM helps in this contest.Wojtek Kulikhttp://www.blogger.com/profile/09788309657571259554noreply@blogger.com0tag:blogger.com,1999:blog-7359347711449723055.post-71991574695661990972009-01-13T09:59:00.000+01:002009-01-13T10:37:03.865+01:00Introduction<span style="font-family:verdana;">Hi!</span><br /><br /><span style="font-family:verdana;">My name is <span style="font-weight: bold;">Wojtek Kulik</span>. I used to hide under nickname "<span style="font-weight: bold;">photek</span>" (guess why, a limited collection handshake offered for the first correct solution; HINT: there are TWO reasons), but from now on I'll be using my real name only. I wish I could change my team's name, but apparently it's not possible (that means I've slightly polluted the leaderboard - sorry for that).</span><br /><br /><span style="font-family:verdana;">To quote Terry Pratchett - I live behind a keyboard in Warsaw (Poland), working on my startup project. As it's related to prediction, I decided to give a try in Netflix Prize challenge, hoping that success of my startup depends on the success of my approach to this challenge.</span><br /><br /><span style="font-family:verdana;">I've managed to get into TOP-40 recently. But to be honest, it's not enough for me... I've got plenty of ideas on my TODO list; unfortunately my current bottleneck is computing power.</span><br /><br /><span style="font-family:verdana;">Enough writing. Time to make a submission :-)</span>Wojtek Kulikhttp://www.blogger.com/profile/09788309657571259554noreply@blogger.com8