In the last week I spent some time preparing a presentation about Web 2.0, data mining, text analysis and related topics. Among these, I discussed a bit of graph theory and clustering. To show a good demo, I fired up Processing to demonstrate how clustering and graph theory work together to create a nice visualization of tag clouds.

I have recently started playing with Amazon SimpleDB, part of the Amazon cloud computing offering, which is basically equivalent to Google Bigtable. Being a ruby enthusiast, I decided to use the right_aws gem from RightScale. The only problem, is that right_aws still does not support batch attribute insertion, which severely limit performances. Since I’m planning to use Amazon SDB for BayesFor, where we need performance, I implemented it. You can find the code in sdb_batchput.rb

While working on some UI design today, I wanted to introduce a CSS effect where one div would scroll underneath another, with a nice shadow effect. Nothing new, you can get an idea right from the thumbnail here to the left, or following the link to the demo. I googled hoping to quickly find some ready made CSS to copy but couldn’t find it, so I decided to write a simple HTML page on my own to reproduce it. UPDATE: Published the code as a gist.

I released on github a small project called Live Javascript Editor. LJE is a simple javascript app that lets you type and execute Javascript code and snippets on the fly. Its main purpose is to help a speaker present and illustrate Javascript code to an audience, like you would do during a tech conference.