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.

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:

Comparison diagram of sky scraper
Astronomic cluster diagram of the Messier 3 globular cluster
Biositemap diagram
Cluster chart in brainstorming

In architecture a comparison diagram is sometimes called a cluster diagram.^[1]
In astronomy diagrams of star clusters, galaxy clusters or globular clusters.
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".^[2] Also, the term cluster diagrams is sometimes used as synonym of mind maps".^[3]

In computer science more complex diagrams of computer networks, computer architecture, file systems and internet can be considered cluster diagrams.
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".^[4]