Treemaps represent a simple way of visualising hierarchical data (e.g. county, state, town … ) in a two dimensional format – usually rectangles within rectangles. This embedding of smaller rectangles within larger ones represents the hierarchical ordering, and both size and colour of rectangles can contain relevant information. While the visualisation is simple the software is not, which is why only the more advanced commercial packages include treemaps. Here are some free libraries, add-ins and code to create treemaps.
Excel – A treemap add-in for Excel. Free demo version limited to 50 data points.
JTreemap is the only java, open-source and maintained library for treemapping. JTreeMap components are released under the business-friendly Apache 2.0 license.
Prefuse supports a rich set of features for data modeling, visualization, and interaction. It provides optimized data structures for tables, graphs, and trees, a host of layout and visual encoding techniques, and support for animation, dynamic queries, integrated search, and database connectivity. Prefuse is written in Java, using the Java 2D graphics library, and is easily integrated into Java Swing applications or web applets.
treemap – The goal of the TreeMap Java Library is to provide a library to ease the implementation of treemap visualization.
SquareMap – A simple wxPython control to display hierarchic data as a recursive set of nested squares, each of which represents the relative size of a given child within its parent.
Treemap is an open-source Treemap generator script written in Python.