Response: Treemaps can be constructed using the googleVis package. This is an R interface to Google Charts API, allowing users to create interactive charts based on data frames. Charts are displayed locally via the R HTTP help server. A modern browser with an Internet connection is required and for some charts Flash. The data remains local and is not uploaded to Google. Treemaps are usually rectangles placed adjacent to each other. The size of each rectangle is directly proportional to the data being used in the visualization. Treemaps have been used to plot the news on the web by Newsmap.jp. They have also been applied in financial websites such as smart money to visualize financial market movements.