Fri

Jul 28
2006

Tim O'Reilly

Tim O'Reilly

Treemap on Rails

Andy Bruno, who developed the treemap code that we use for our Bookscan data visualizations, has created a new Rails implementation called acts_as_treemap, according to a report by Rob Orsini, author of The Rails Cookbook, who blogs on Rails-related topics at tupleshop.com.

If you're a fan of data visualization, as I am, you'll be excited both about getting your hands on Andy's Ruby treemap code and on Rob's clear description of how it works. And heck, Andy even applied it to an example data set that is fascinating in and of itself: SourceForge projects.

Here's the resulting treemap view:

SourceForge Treemap

This visualization uses the SourceForge project name for labeling each region of the treemap; the size of each region is be based on the number of downloads for the current month, and the color of each region conveys information about the rate of change in the number of downloads for each project. While the color-scheme is a bit different than we use for the book visualizations, green means up, red means down, and the paler colors are in-between. There's a bit of overlaid information about categories, but the treemap doesn't really organize the downloads by category like we do with book sales. But it's still pretty interesting to pick out the biggest downloads.

And what's more, if you like this kind of visualization, Andy and Rob have now made it easy for you to apply it to your own data sets.


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Comments: 7

  adamsj [07.28.06 06:46 AM]

This is sweet! The first time I saw Treemap (OSCON 2004), I wanted to use it, but it just wasn't worth learning Java for.

  Sean Boisen [07.28.06 08:33 AM]

If you're a new fan of treemaps, you should definitely look at the treemap work at U Maryland's Human-Computer Interaction Lab (http://www.cs.umd.edu/hcil/treemap/): they pioneered this area.

  falcon [07.29.06 03:34 AM]

I guess I'm the only person left in the world who hates treemaps. Lots of information is packed in them, but it is far easier to have a few higher level bar graphs than a single tree map (beyond the top few categories, you can't see the detail anyway).

  Tim O'Reilly [07.29.06 08:25 AM]

falcon -- we never use treemaps in isolation in our own tools. The treemap provides an interface to the data mart. In the dynamic version we use, clicking on any square takes you down to the next lower level of the hierarchy. There's also a tooltip that pops up vital statistics when you mouse over any square. And finally, ctrl or cmd-clicking on a square pops up a "dashboard" (I've shown pictures of some of those) that gives way more details about the data behind the category.

In short, we think of it as an interface, not a graph. Unfortunately, we can't give fuller access to the live application and data mart, both for competitive reasons and because our license to the book data allows us to publicize it only in the context of promoting books. Nielsen would likely look askance at giving the world full access to their data.

  Mike [08.01.06 04:42 AM]

Hi,
If you like treemaps and want to try them out in a easy fashion, look at Panopticons new Explorer. It's great! And it's free!
Drag-and-drop your excel files or access database and see the data in a treemap. Quite cool to drag in a folder on your computer and see it all categorized and displayed in a map.

Here you find the Exloprer:
http://www.panopticonexplorer.com

  hb [08.12.06 03:27 AM]

Have a look at http:/www.macrofocus.com/treemap.

It's nice

  hb [08.14.06 12:09 PM]

I like treemap very much.
Now I have downloaded a pretty nice tool.
Here you will find
www.macrofocus.com/treemap

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