A TreeMap chart is a type of data visualization tool used to display hierarchical data structures in a nested, hierarchical manner. It is a type of tree diagram often used in information visualization, particularly in data analytics, where it can represent various forms of hierarchical data, such as organizational structures, file directory structures, or nested categories.
Some common varieties of TreeMap charts:
- Squarified TreeMap: In squarified TreeMap charts, the rectangles are laid out so that each child rectangle maximizes its size, resulting in a more space-filling and aesthetically pleasing layout. This layout makes it easier to compare the sizes of the rectangles. Squarified Treemaps are widely used for visualizing hierarchical data.
- Slice-and-Dice TreeMap: In this type of TreeMap, the parent rectangle is divided into smaller rectangles horizontally (slice) or vertically (dice). This straightforward approach can lead to uneven rectangle sizes, making it less space-efficient than squarified TreeMap layouts.
- Binary TreeMap: Binary Treemaps represent hierarchies as a binary tree, where each node has two children. The hierarchy is depicted by splitting the parent rectangle into two child rectangles, and this process continues recursively. Binary Treemaps are easy to understand but may not make the most efficient use of space.
- Ordered TreeMap: Ordered Treemaps are similar to squarified Treemaps, but they prioritize the order of items within each level of the hierarchy. This layout can help maintain a consistent order or alignment of items, which may be necessary for some applications.
Many data visualization libraries and software tools, like D3.js and Microsoft Excel, can create TreeMap charts.
List of recommended resources #
For a broad overview #
A Study on the Effectiveness of Tree-Maps as Tree Visualization Techniques
This article studies tree structure visualization techniques as well as looks at the effectiveness of treemaps in visualizing hierarchy.
A Taxonomy of Treemap Visualization Techniques
This conference paper gives a broad overview of treemap visualization techniques used for representing hierarchically structured data.
This data visualization catalog provides a brief overview of treemap charts used for hierarchically visualizing data.
For in depth understanding #
Data Visualisation: A Handbook for Data Driven Design
This book by Andy Kirk gives an extensive understanding of various data visualization techniques, providing a step-by-step thorough explanation.
Effective Data Visualization: The Right Chart for the Right Data
Written by Stephanie D. H. Evergreen, this comprehensive how-to guide shows readers how to create Excel charts and graphs that best communicate their data findings.
Case study #
An interactive meta-analysis of MRI biomarkers of Myelin
This paper uses treemap charts of the studies considered for the meta-analysis, organized by MRI measure of MRI biomarkers of Myelin.
This research paper makes use of the treemap chart to represent the perception of the most ethically problematic technologies in industry.
References #
Treemaps: Data Visualization of Complex Hierarchies
