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 can be seen as a type of network diagram, and a tree diagram a tree type of network diagram.
Types of cluster diagrams
Specific types of cluster diagrams are: Image:Skyscrapercompare.svg|Comparison diagram of sky scraper Image:M3 color magnitude diagram.jpg|Astronomic cluster diagram of the Messier 3globular cluster Image:Biositemap iTools NCBC.png|Biositemap diagram Image:EvaporacaoDeNuvem.png|Cluster chart in brainstorming
In brainstorming a cluster diagrams is also called cloud diagram. They can be considered "are a type of non-lineargraphic 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". Also, the term cluster diagrams is sometimes used as synonym of mind maps".
Image:Motherboard diagram.svg|Computer architecture diagram of a PC Image:IEEE 802.15.4 cluster tree.png|Computer network diagram Image:WorldWideWebAroundWikipedia.png|Internet diagram Image:NDE Context Diagram.svg|System context diagram
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 , the called coupled cluster diagram is a "simple diagrammatic formalism popularized by Kucharski and Bartlett by which one may construct the coupled cluster energy and amplitude equations far more quickly than by direct application of Wick's theorem".