Notes on codes, projects and everything
Information Retrieval
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Further Hack on the Multi-Dimensional Approximate Neighbour Search
Traversing a tree structure often involves writing a recursive function. However, Python isn’t the best language for this purpose. Therefore I started flattening the tree into a key-value dictonary structure. Logically it is still a tree, but it is physically stored as a dictionary. Therefore it is now easier to write a simple loop to traverse it.
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Approximate Neighbour Search in Multiple Dimensions
In the previous post, I re-implemented Annoy in 2D with some linear algebra maths. Then I spent some time going through some tutorial on vectors, and expanded the script to handle data in 3D and more. So instead of finding gradient, the perpendicular line in the middle of two points, I construct a plane, and find the distance between it and points to construct the tree.
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Re-implementing Approximate Nearest Neighbour Search
Recently I switched my search code to Annoy because the input dataset is huge (7.5mil records with 20k dictionary count). It wasn’t without issues though, however I would probably talk about it next time. In order to figure out what each parameters meant, I spent some time watching through the talk given by the author @fulhack.
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Information Retrieving with ….. a lot of libraries
Implementing a Information Retrieval system is a fun thing to do. However, doing it efficiently is not (at least to me). So my first few attempts didn’t really end well (mostly uses just Go/golang with some bash tricks here and there, with or without a database). Then I jumped back to Python, which I am more familiar with and was very surprised with all the options available. So I started with Pandas and Scikit-learn combo.
Random Posts
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Over-doing a task: reading CSV file in #golang
I was invited to try Go (the programming language, not that board game) a few months ago, however I didn’t complete back then. The main reason was because it felt raw, compared to other languages that I know a fair bit better (for example Ruby). There was no much syntatic sugar around, and getting some work done with it feels “dirty”.
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Drafting my first progress report
Just managed to migrate all my blog sites to one centralized multi-site, so no more
half-bakedsolution and hopefully this brings better plugin compatibility. I have not check with other related services (like Google Webmaster Tools) whether this cause any breakage though. Well, the main purpose of this blog post is actually a draft of what I did for the past two months for my postgraduate programme. Yea, I should have posted more stuff to this blog (just realized that my last post here is already like half a year ago). -
Semantic Network
Recently the term “Semantic Web” becomes extremely popular that Sitepoint blogs keep posting articles on this topic (1, 2). In my college days, I learned about Semantic Network and I wonder if there is some relationship between them. I’m not sure whether I get the concept correctly but in this article I would like to revise a bit on semantic network before going to semantic web. Please correct me if I’m wrong.
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Webmail Checker Alpha for MeeGo Harmattan
After shifting all my instant messaging accounts to my Nokia N9, I stopped getting email alerts via Adium. Therefore, when I finally remember to check my mailboxes, they are already loaded with exploding amount of mails (mostly junk and newsletter though). I don’t fancy doing my email stuff with my device, and don’t feel like installing a webmail checker to my browser, hence this simple little script is written for my phone.
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Sync’ MP4 Tracks through MTP
I’m not sure why Windows Media Player 11 doesn’t like mp4/aac format but not being able to transfer my tracks in mp4 through MTP to my N81 really piss me off. At first I installed Songbird 1.0.0 to try synchronizing the tracks through the MTP addon but it doesn’t even play *.mp4 tracks out of the box under Windows XP SP3 (although it claimed otherwise). Weird thing happens when I was trying to synchronize anyway by having the files renamed to *.mp4 extension and it succeeded but without any meta-tag information.
