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

• New directory structure

  While the previous file structure works well, I decided to tune some details before deploying the latest WordPress release. Besides that, I also started a new theme development project after my last theme which was developed more than 2 years ago. Thankfully, everything seems to work so far.

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• Regression with Annoy (cont’d)

  After a year and half, a lot of things changed, and annoy also changed the splitting strategy too. However, I always wanted to do a proper follow up to the original post, where I compared boosting to Annoy. I still remember the reason I started that (flawed) experiment was because I found boosting easy.

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• Database transactions involving prepared statements

  I was thinking whether it is possible to avoid exposing PDO and PDOStatement objects to the users of my database library (mainly just me). While I was working on my project I sort of notice that there is a almost fixed pattern whenever I work with the database. With this in mind, I added in some new functions to the library, and decided to make a quick release for this.

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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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• Building Dynamic Form the hard way with React-Redux

  Javascript is getting so foreign to me these days, but mostly towards a better direction. So I recently got myself to learn react through work and the JSX extension makes web development bearable again. On the other hand, I picked up a little bit on Vue.js but really hated all the magic involved (No I don’t enjoy putting in code into quotes).

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