# Cluster diagram

A Cluster diagram or clustering diagram is a general type of diagram, which represents some kind of cluster. A cluster in general is a group or bunch of several discrete items that are close to each other. [1]

The cluster diagram figures a cluster, such as a network diagram figures a network, a flow diagram a process or movement of objects, and a tree diagram an abstract tree. But all these diagrams can be considered interconnected: A network diagram can be seen as a special orderly arranged kind of cluster diagram. A cluster diagram is a mesh kind of network diagram. A flow diagram can be seen as a line type of network diagram, and a tree diagram a tree type of network diagram.

## Types of cluster diagrams

Specific types of cluster diagrams are:

• In architecture a comparison diagram is sometimes called a cluster diagram.[2]
• In brainstorming a cluster diagrams is also called cloud diagram. They can be considered "are a type of non-linear graphic organizer that can help to systematize the generation of ideas based upon a central topic. Using this type of diagram... can more easily brainstorm a theme, associate about an idea, or explore a new subject".[3] Also, the term cluster diagrams is sometimes used as synonym of mind maps".[4]

• In information visualization specific visual representation of large-scale collections of non-numerical information are sometimes drawn in the shape of a cluster diagram.
• In quantum field theory for example, according to Crawford (1998), the called coupled cluster diagram is a "simple diagrammatic formalism popularized by Kucharski and Bartlett [in 1986] by which one may construct the coupled cluster energy and amplitude equations far more quickly than by direct application of Wick's theorem".[5]

## References

1. ^ Lemma cluster at Wiktionary. Retrieved Sept 18, 2008.
2. ^ Illustration called City of London Skyscraper Cluster Diagram at skyscrapernews.com. Retrieved 18 september 2008. Comment: This illustration depicts a "comparison diagram", but yet is called a "cluster diagram".
3. ^ Cluster/Cloud Diagrams at enchantedlearning.com. 2003-2009. Accessed Nov 17, 2009.
4. ^ Cluster diagrams are another way to mind map by starting with the keywords first. at www.brainstorming-that-works.com. Retrieved 18 september 2008.
5. ^ T. Daniel Crawford (1998). "An Introduction to Coupled Cluster Diagrams". In: Reviews in computational chemistry. Kenny B. Lipkowitz, Donald B. Boyd eds. (2000) Vol 14. p.77. (Retrieved 18 september 2008).