A treemap is a type of visualization that helps to see the trees behind the forest. Treemaps display hierarchical information in a series of clustered rectangles, which together represent a whole. The size of each box represents a quantity and usually are represented with colors in order to add another dimension or to represent any number of values, but it is often used to categorize the various boxes within the treemap.
If your data is a hierarchy, a treemap is a good way to show all the values at once and keep the structure in the visual. This is a quick way to make a treemap in R.
If you need to create Treemap in Excel, Databison has a great (but not free) treemap addin for Excel that you can install that will help to make treemaps in the spreadsheet. Once you have the graphics rendered in Excel you can export to image or copy and paste in your PowerPoint presentation.
Treemaps can also be used to represent complex data and hierarchies, for more info you can refer to Treemaps for space-constrained visualization of hierarchies.
- Free tools can be found for example SequoiaView (Download). It is freeware and make you possible to generate treemaps from your hard drive to have a view about what folders and files have more size.
- Excel Treemap addin is not free, but for $15 you can access this addin and generate your own treemaps in Excel.
- If you need to create treemaps for free, you can take a look to Google Visualization API and Many Eyes from IBM.
- Wikipedia also has an interesting review about treemap software, mentioning Treemaper and the popular Macrofocus Treemap (www.treemap.com).
- If you are an R programming language enthusiast, you can create treemaps easily using your own data and then export the resulting graphic. This tutorial from FlowingData explains step by step how to do it.
If you need to see examples of treemaps, then there are lot of resources where you can find some good ones.
Other nice treemap examples can be found in 10.000 words. For example:
Obama 2011 Budget Proposal How it is Spent.
News and press coverage (Newsmap example)
BBC News for top 100 websites
In the stock market you can also find some good examples using Treemap for example here.
Or Smart Money can show you another map of the market.