mindspill

Observing Cults

Fri, 18 Jul 2008 19:13:50 GMT

This is one of the first visualization research images I created. It's a composite image of the same cult network, represented in different ways. The whole network is represented as a pixel matrix. Part of the network is represented as a node-link graph diagram. Finally the graph is a detailed view of an individual node in the network.

Some links posted on Twitter

Mon, 19 May 2008 02:00:38 GMT

These are a summary of links posted on my twitter profile this week for the benefit of those who aren't using twitter yet.

Article about fostering innovation at Pixar

Listening to moloko but now giving a try to infected mushroom.

Just learnt about the bradley effect.

Perspective aricle by doshdosh about getting twitter followers.

Interesting Infovis videos.

Processing ported to Javascript

Fri, 09 May 2008 20:16:52 GMT

Processing is an easy to use programming language designed to make creating data visualizations easier. Processing simplifies the syntax of writing programs that draw graphics and use animation. The language was designed to be easy enough to be used by designers, to abstract most of the complication of writing the same functionality in Java. Each Processing application is finally converted into Java and can be either uploaded to a website as an applet or as a standalone Java program.

John Resig, has now ported the Processing language to Javascript. Using this library now you can write processing code that gets dynamically converted into Javascript and loaded directly in the browser, without having to load a Java Applet. Resig has a long list of examples using his Processing Javascript Library.

Giving Twitter another chance

Fri, 09 May 2008 05:05:07 GMT

I've decided to give Twitter another try. For those unfamiliar with the service, twitter is a website where you can post (or send) a small message to people who are interested in hearing it. For people to see your messages they have to subscribe to your posts by following you on twitter. These messages can be viewed either from the twitter website, or using special twitter clients, or even getting them on the phone by SMS.

Originally the service was intended to let your friends know what you're up to. It was something similar to setting you status in facebook, or your personal message in MSN Messenger. Now apart from it's original use, twitter is used to send all sort of messages, like for example links to interesting sites, or asking questions to people who are following you. It's a sort of cross between instant messaging, chatting and mini-blogging.

I tried twitter a couple of months ago, way before it got all the hype. I used it mainly for posting my status to friends, but since there weren't many of my friends using it yet it was pretty useless. Now I'm giving it another go, hoping to make some new friends. If you want to follow me on twitter to see what I'm up to this is my profile. I still have to figure out how to find interesting twitters though.

Now with twitter I have to decide what should get blogged and what should get twitted :) Well, for posts more than a sentence long I'll have to blog them, but I might start posting less general appealing links (like computing links) on twitter more than on the blog.

How to get the miss hooked on gadgets?

Wed, 07 May 2008 17:05:09 GMT

Get her one of these Roomba iRobots... Click image for video

Baseball Visualizations

Tue, 15 Apr 2008 17:19:20 GMT

The new baseball season has just started and like every year the race is on to win the World Series. Baseball is probably the richest sport when it comes to statistical data and analysis, yet for a sport so rich in statistical data a search in the custom google data visualization search engine, and the infovis image search database yielded very few results. These are some of the more interesting baseball visualizations I found around.

Salary vs Performance - Ben Fry, one of the authors of the Processing programming language uses his freely available tool to visualize which baseball teams are spending their money well, and how does each team position changes over the course of the season? The last applet uploaded looks at the teams and their salaries in 2007.

Baseball Visualization Tool - This is a commercial tool that uses a pie chart to guide the manager whether to pull the pitcher or not. The fuller the pie chart the more the pitcher should be changed.

Baseball race - This visualization tracks the progress of each team in a season as the season progresses. The dataset used for this application starts from 1901 and continues till the present day. The data is freely available from Retrosheet, a baseball scores database.

Bivariate Baseball Score Plots - The bivariate baseball score plots present summary information for MLB teams game scores. The scores are visualized using a bivariate baseball score plot with each game being a point in a two-dimensional grid.

Chernoff Faces baseball managers - A visualization coming fresh off the press that uses Chernoff faces to display baseball manager stats. The features of the face like face height, width, nose size, mouth curvature, etc. change according to the values of the attributes they are representing.

Mitchell Report Visualization - In December 2007 a 409 page report was published detailing the use of steroids in Major League Baseball. A social network of connections between players and trainers mentioned in the Mitchell Report was created using Social Action, a tool developed by the HCI Lab of Maryland University.

Bill James - A video interview and a newspaper interview with the most popular baseball statistician, and also the inventor of the term used to describe baseball analysis - Sabremetrics.

Using faces to display data

Fri, 11 Apr 2008 15:08:01 GMT

Dr. Steve C Wang used a data visualization technique called Chernoff faces to display some characteristic of baseball managers in 2007. The technique was developed by Herman Chernoff in 1973, and the idea behind it is to display different data attributes as facial features such as curvature of the mouth, length of nose, direction of eyebrows. In Dr Wang’s graphic, the number of lineups used by the manager is the length of face, width of eyes and ears; the number of pinch-hitters is the width of the hair, and the width of the face. Using this technique one can display many different attributes of a data set in a single face then allow the user to compare the different faces to analyse the data. In fact Chernoff claims that up to 18 data elements can be displayed using this method, allowing the user to visually cluster the data.

How effective are Chernoff faces in conveying information? Maybe the faces do not covey information at first glance, and they need a lot of referencing to the face legend, however I think they make an interesting and fun way of displaying information. The sole fact that this technique made the pages of the NY Times is enough proof of this. I’m sure that if the same data was displayed with bar graphs and pie charts it wouldn’t make any headlines. Most user studies in visualisation take into account the efficiency (speed in answering / accuracy of answer) of the technique, however techniques like Chernoff face maybe aren’t suited for answering questions fast, but they are catchy and media friendly.

More on Chernoff Faces
   Critique by Robert Kosara
   An Experimental Analysis of the Effectiveness of Features in Chernoff Faces
   Chernoff Faces in Psychology

Implementation
   Java
   R
   Excel

CAPTCHA's used to digitise books

Fri, 28 Mar 2008 15:01:46 GMT

CAPTCHA's are those annoying pictures with characters on them that you have to type to prove to a website that you're human. They're meant to prevent automatic programs to mimic humans and spam. While they undoubtedly are a great good for the internet, they're also a bloody waste of time. The inventor of the CAPTCHA's Luis von Ahn, realised this and decided to put this human effort to good use - to convert old books into electronic form.

Listen to this interview with Luis von Ahn at the IT Conversations Network

How to watch better quality videos on YouTube

Tue, 04 Mar 2008 16:17:34 GMT

Youtube is now making some high resolution videos available. If you find a video you'd like to watch, you can add the following text to the webpage address, "&fmt=6" (without the quotes) to get a better picture. For the higher quality version you might need to wait a bit longer than for the normal version, because the size of the file is bigger, so it takes more time to download.

For example you can take a look at these two videos and compare the difference:-

http://www.youtube.com/watch?v=QAE2-FQHkok
http://www.youtube.com/watch?v=QAE2-FQHkok&fmt=6

For the more technically oriented, there's a greasemonkey script available to automatically show the high-res video if available.

Also if you add "&fmt=18" instead of &fmt=6 you'll get the video in mp4 format instead of the usual .flv format usually used by youtube.

Via Hackzine

Data Mining and Info Vis for this week

Mon, 03 Mar 2008 18:55:20 GMT

Nat Torkington from O'Reilly Radar published an interesting weekly roundup post of the Data Mining and Visualization posts. The most interesting posts mentioned are: Catching a poker cheat with data mining, SNA toolkit for R and a link to a machine learning blog called Machine Learning (Theory)

3 Links

Thu, 21 Feb 2008 03:10:28 GMT