Kernel Canonical Correlation Analysis code for Matlab

I've made a package with kernel canonical correlation analysis (KCCA) code for Matlab, as part of the experiments I did for a paper. While there are some other packages out there, most notably David Hardoon's KCCA code [1] and Francis Bach's kernel ICA code [2], I wanted a KCCA implementation that included a demo file in addition to the KCCA functions, and I wanted it to be very fast.

The code performs standard regularized KCCA and it includes a demonstration on some synthetically generated data. It can be modified easily to work on external data sets and to use custom kernel functions. The KCCA implementation decomposes the kernel matrices using incomplete Cholesky decomposition, which does not require to calculate the entire kernel matrix (see [2] for more details). The code contains different forms of the generalized eigenvalue problem, all of which yield very similar results. A demo that performs full KCCA without decomposing the kernel matrices is also included.

Download the KCCA code here:
http://sourceforge.net/projects/kmbox/files/packs/

The package is part of my Kernel Methods toolbox, which is still very much in beta. Suggestions are welcome.

References:
[1] D. R. Hardoon, S. Szedmak and J. Shawe-Taylor, "Canonical Correlation Analysis: An Overview with Application to Learning Methods", Neural Computation, Volume 16 (12), Pages 2639--2664, 2004.
[2] F. R. Bach and Michael I. Jordan. "Kernel Independent Component Analysis", Journal of Machine Learning Research, volume 3, pages 1-48, 2002.

Comparing the weather forecast for two cities

Going out for the weekend but can't make up your mind between two great places? Wolfram Alpha to the rescue! I found out you can compare weather forecasts with it too. Just use their weather forecast with the "versus" operator, like in this recent query of mine

and up pop the results:

For less well-known cities you might give Wolfram Alpha a hand by adding some parentheses etc.:

Happy walphing!

An exquisit blank HTML page

Fancy hacking together a quick single-page web site? No? Well I do. Just in case you change your mind, here's a high-quality blank HTML page you can use as a starting point. It's transitional XHTML and has utf-8 encoding, so that should allow for doing quite a few crazy things.

Spanish DNI and NIE letter calculator

As I couldn't find this really well done anywhere online, I made a small tool to calculate the letter of the Spanish DNI. For expats living in Spain, you can use it to calculate the letter of a NIE too.

Here it is: Calculadora de letra de DNI y de NIE.

Google reverse image search on desktop

Google finally adjusted their Goggles service for the desktop, so we can now also add their service to list of reverse image search tools, which already included the algorithms of TinEye, Cydral and GazoPa among others. First results show it's a winner, returning more identical results, more visually similar images, and interesting context information. Go to images.google.com to see if it's available in your region.

To commemorate the occasion, I released a new version of RevEye, the Chrome plugin to perform reverse image searches. It now includes searches by Google, TinEye, Cydral, and I've added Yandex and Baidu to the list since they also do pretty well.

RevEye v1.3 is a free download available from the chrome web store.

RevEye: Even more reverse image search

Google asked me to change the name of my Chrome plugin "ChromeEye" into something that did not violate their terms. Fair enough. I changed it to "RevEye", and took the opportunity to make some changes to the user interface as well.

First, I added the Cydral engine to the list of reverse image search services included, since it has been producing some very nice results lately.

Second, I added an option to change the context menu: You can now choose either to use one default search engine, or to have a cascaded menu with all options on every search. My favorite option is the one that opens all services in different tabs.

These changes basically make RevEye a "meta reverse image search tool", since it now includes the complete functionalities by the TinEye, GaZoPa or Cydral plugins. So off you go then! Install it and have fun tracking images.

RevEye v1.2 is a free download available from the chrome web store.

More reverse image search: ChromeEye v1.0

Yesterday I released a new version of my reverse image search extension "ChromeEye" for Google Chrome. While the first version was simply a bridge to the reverse image search engine TinEye, the new version 1.0 includes the option to use different search engines. At the moment that means images can be sent either to TinEye or to GazoPa. TinEye, which seems to be most popular reverse image search engine these days, looks mainly for exact matches. GazoPa uses a very different algorithm, based on visual features, with sometimes surprising results. Both are still improving their algorithms, obviously, so we´ll keep an eye on them.

That said, ChromeEye is now a plugin for reverse image search in general, and I will be including more search engines in the future. Note also that it is using the right click context menu for image searches. This was a much asked for option in the previous version, but technically not possible (due to Chrome restrictions) when I released it.

ChromeEye v1.0 is a free download available from the chrome extensions directory and from the chrome web store.