Information Retrieval

• 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.

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Random Posts

• What’s so difficult about HTML?

  I am not going to waste time telling stories that inspire this post, as most people would have already heard something similar constantly. This is not a mythbuster kinda post, so don’t expect a scientific proof to the answer of the question. Instead, through this post, I hope to break the impression that claims composing a HTML document is difficult.

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• MVC: Kohana vs. Zend Framework

  After comparing my own implementation of MVC with CodeIgniter’s, now I’m comparing Kohana’s and Zend’s. I have just shifted from CodeIgniter to Kohana recently in work and is currently learning on how to use Zend Framework to build my web-app. As everybody knows, Zend Framework is more like a collection of library classes than a framework a la Ruby on Rails, using MVC in Zend Framework would require one to begin from bootstrapping stage. However, in Kohana, just like other frameworks, bootstrapping is done by the framework itself so the developer will get an installation that almost just works (after a little bit of configuration).

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• Slideshow using Scriptaculous

  I need a slide show script for my portfolio pages but couldn’t find a good one anywhere so I decided to write one myself. The slide show script will be able to display image and the respective description in a predefined order. However, in this version, visitors would not be able to directly jump to a particular slide yet. The script is written in prototype‘s object-orientation approach hence you need to have prototype called.

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• Working Life

  I didn’t realize that I have been working for 3 weeks until the Labour Day which was a public holiday. Many things happened in these few weeks and I am still struggling to catch up with it. My superior and colleagues have been very helpful and offered me some helpful tutorials and books. I was instructed to build a event scheduler application using codeigniter in the first week and then work on a side project that extends a form using DOM methods and properties.

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• Picking Up Category Theory (and eventually Haskell)

  I don’t quite remember when did I first heard about Category Theory, but the term stuck in my head for quite a while. Eventually I attempted to start looking for tutorials on the topic, but it is hard to find one that I actually understand. Most of them are either leaning too much to the Mathematics side, or too much to the Programming side.

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