Regular
From Wikipedia, the free encyclopedia
In ordinary English, regular is an adjective or noun used to mean in accordance with the usual customs, conventions, or rules, or frequent, periodic, or symmetric.
The term regular also refers to:
- In the military, a regular unit is a military unit that is part of the regular forces (not militia or military reserves). For example, the US 101st Airborne Division is a regular unit, while the 1st US Army (Reserve) is not. See Regular Army for usage in the U.S. Army.
- A person who appears often at a certain location and may know others who are also there often, whether out of want or occupation. For example, a regular can be one who goes to a certain coffee shop everyday, so often that the employees know him or her.
- Someone who defecates roughly the same amount and at the same time every day.
- In Freemasonry, regularity refers to the constitutional mechanism by which Grand Lodges or Grand Orients give one another mutual recognition.
- In conjugation, a regular verb is a verb that inflects normally.
Mathematical meanings include:
- In geometry, a geometric figure is regular if it is symmetric. See regular polygon or regular polyhedron.
- In linear algebra, a regular matrix is an invertible matrix.
- In graph theory, a regular graph is a graph such that the all the degrees of the vertices are equal.
- In computer science, particularly formal language theory, a language is regular if it can be represented by a regular expression.
- In topology, a regular space is one in which points are closed and any point can be separated from any closed set by open sets.
- In algebraic geometry, a function is regular on a variety if for every point there exists an open neighborhood so that the function restricts to a rational function whose denominator does not vanish in that neighborhood.
- In information theory, data with regularity has less entropy than its representation suggests. For example, English prose is quite regular because most random sequences of alphabetic and punctuative characters are not valid English prose.
- In analysis, regularity refers to the degree of differentiability or smoothness of a function.