In mathematics, a transformation or self-map [1] is a function f, usually with some geometrical underpinning, that maps a set X to itself, i.e. f: X → X. [2] [3] [4] Examples include linear transformations of vector spaces and geometric transformations, which include projective transformations, affine transformations, and specific affine transformations, such as rotations, reflections and translations. [5] [6]
While it is common to use the term transformation for any function of a set into itself (especially in terms like " transformation semigroup" and similar), there exists an alternative form of terminological convention in which the term "transformation" is reserved only for bijections. When such a narrow notion of transformation is generalized to partial functions, then a partial transformation is a function f: A → B, where both A and B are subsets of some set X. [7]
The set of all transformations on a given base set, together with function composition, forms a regular semigroup.
For a finite set of cardinality n, there are nn transformations and (n+1)n partial transformations. [8]
In mathematics, a transformation or self-map [1] is a function f, usually with some geometrical underpinning, that maps a set X to itself, i.e. f: X → X. [2] [3] [4] Examples include linear transformations of vector spaces and geometric transformations, which include projective transformations, affine transformations, and specific affine transformations, such as rotations, reflections and translations. [5] [6]
While it is common to use the term transformation for any function of a set into itself (especially in terms like " transformation semigroup" and similar), there exists an alternative form of terminological convention in which the term "transformation" is reserved only for bijections. When such a narrow notion of transformation is generalized to partial functions, then a partial transformation is a function f: A → B, where both A and B are subsets of some set X. [7]
The set of all transformations on a given base set, together with function composition, forms a regular semigroup.
For a finite set of cardinality n, there are nn transformations and (n+1)n partial transformations. [8]