Regular
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.
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.
