2017 October

• Understanding potree hierarchy file

  One of my recent tasks involving crawling a lot of geo-tagged data from a given service. The most recent one is crawling files containing a point cloud for a given location. So I began by observing the behavior in the browser. After exporting the list of HTTP requests involved in loading the application, I noticed there are a lot of requests fetching resources with a common rXXX pattern.

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Random Posts

• 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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• Implementing Fuzzy c-means in Clojure

  I was asked to evaluate fuzzy c-means to find out whether it is a good clustering algorithm for my MPhil project. So I spent the whole afternoon reading through some tutorial to get some basic understanding. Then I thought why not implement it in Clojure because it doesn’t look too complicated (I was so wrong…).

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• 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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• Oh NO! My print output is chopped!

  So my cheat with dask worked fine and dandy, until I started inspecting the output (which was to be used as an input for another script). While the script seemed to work fine, however when I started to parse each line I was hit with some funny syntax errors. After some quick inspection I found some of the lines was not printed completely.

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• FSM-based Workflow System

  Recently I am being assigned to work on a FSM based workflow system to enable my other colleagues to use it in their application. I am rather impressed with the simplicity of the workflow system (initially designed by my Technical Director) and decided to post some notes here. The workflow system was developed for CodeIgniter PHP framework and Drupal CMS.

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