Noun

(en noun)

A plan, drawing, sketch or outline to show how something works, or show the relationships between the parts of a whole.

*{{quote-magazine, date=2012-03

, author= , title=Pixels or Perish , volume=100, issue=2, page=106 , magazine= citation , passage=Drawings and pictures are more than mere ornaments in scientific discourse. Blackboard sketches, geological maps, diagrams of molecular structure, astronomical photographs, MRI images, the many varieties of statistical charts and graphs: These pictorial devices are indispensable tools for presenting evidence, for explaining a theory, for telling a story.}}

Electrical diagrams show device interconnections.

A graph or chart.

(category theory) A functor from an index category'' to another category. The objects and morphisms of the index category need not have any internal substance, but rather merely outline the connective structure of at least some part of the diagram's codomain. If the index category is ''J'' and the codomain is ''C'', then the diagram is said to be "of type ''J'' in ''C ".

Noun

(en noun)

(dated) Generally , a map used to indicate geographically-bound statistical information, typically region-by-region values of a given variable, for example by using different shadings for different ranges of values.

* 1888 October, Dewey, Davis R., "Elementary Notes on Graphic Statistics", in the Massachusetts Institute of Technology Technology Quarterly , Volume II Number 1, published by the students (1888–1889), p. 99,

[…] whether, however, two states with these respective ratios do not consequently sufficiently differ […] as to warrant distinction in the cartogram , is open to question.

* 1895 , "Book Notes", in Academy of Political Science (U.S.) and Columbia University Faculty of Political Science, Political Science Quarterly , Volume X Number 3, Academy of Political Science (1895), p. 560,

The fifth cartogram illustrates the criminal statistics for the period 1882-91, which are of unusual interest because […]

Specifically , a map-like graph where the relative areas of graph regions are proportional not to the relative areas of the land regions they represent, but rather to another quantitative variable, such as population or gross domestic product.