## (note (code cslai))

Notes on codes, projects and everything

# lann

• ### Regression with 2-means clustering Annoy (non-scientific)

So apparently Annoy is now splitting points by using the centroids of 2 means clustering. It is claimed that it provides better results for ANN search, however, how does this impact regression? Purely out of curiosity, I plugged a new point splitting function and generated a new set of points.

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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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• ### Quick experiment, boosting vs annoy

While following through the Statistical Learning course, I came across this part on doing regression with boosting. Then reading through the material, and going through it makes me wonder, the same method may be adapted to Erik Bernhardsson‘s annoy algorithm.

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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.

## Random Posts

• ### Development virtual machines on OS X using VirtualBox and Ubuntu

I have been following this excellent guide written by Benjamin Thomas to set up my virtual machine for development purpose. However, when I am starting to configure a Ubuntu Quantal alpha machine, parts of the guide became inapplicable. Hence, this post is written as a small revision to the previously mentioned guide.

• ### Weekend Code Quiz – Easy Template Parser

A friend of mine recently posted a screenshot containing a code snippet for a fairly straight forward problem. So after reading the solution I suddenly had the itch to propose another solution that I initially thought would be better (SPOILER: Turns out it isn’t). Then mysteriously I stuck myself to my seat and started coding an alternative solution to it instead of playing Diablo 3 just now.

• ### 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.

• ### Setting Up Virtuoso for Redland Under Ubuntu

Just a quick update to the previous post, the virtuoso storage engine works with redland provided the required packages are properly installed (yes, yes, yes, I know I haven’t release my PHP OO wrapper for Redland). Now that the package is installed, we need to do some configuration so that Redland can use it.

• ### Abusing PHP Again: Convert meeTrainer’s CSV to GPX

The Sports Tracker app for my awesome Nokia N9 is not receiving any updates and doesn’t look like things are going to change any time soon. Recently the development team at Sports Tracker published a status update post and sadly there’s no mention of N9 port at all. It’s really sad considering how incomplete the N9 port is at the moment (horrible GPS positioning, no pedometer to name a few).