Treemaps

For the latest chapter, we harnessed the power of Treemaps (history here) to generate a quick-and-dirty visual comparison of objects. The magnitude of some attribute determines the area given to that object in the representation, giving a visual patchwork that conveys the relative weight of each object relative to the others in its class.

To quickly illustrate the power of this method, the chapter starts off with the example of displaying word frequency in Mark Twain's "Following the Equator":

After laying the conceptual foundation, we turn the idea of Treemaps to a more complex and useful application. The final project asks the user to select a directory to start at, and then maps the files and folders contained in that directory to their relative data usage. Opening window:

I selected my "Pictures" folder, and the first screen appears as such:

As one might gather from the picture, the boxes represented are assigned a hue based on their location from the top-left to bottom-right corners. In this screenshot, focus is given to the "2009-11" folder, which brings the brightness of this box up, and simultaneously dims the other boxes in the field. Clicking on a box causes it to display a recursive Treemap of the folder contents inside of it.

This process is demonstrated the screenshot below, which is a zoom in on the folder "Snapshots" and then a highlighting the folder "2009_05_24", which has a Treemap on all of the files found within that folder. Emphasis is on the file IMG_0087.JPG.

One final touch that I want to mention is that the value of each hue is adjusted based on the most recent modification date of each folder/file. The timescale on that, moreover, uses an algorithm that evaluates all objects displayed on the screen and computes a logarithmic approximation of the set. This is displayed in the following screenshot: (mouse emphasis on the folder "2008-12-15")