Affine
# Affine

Affine may describe any of various topics concerned with connections or affinities.

It may refer to:

* Affine, a relative by marriage in law and anthropology
* Affine cipher, a special case of the more general substitution cipher
* Affine combination, a certain kind of constrained linear combination
* Affine connection, a connection on the tangent bundle of a differentiable manifold
* Affine Coordinate System, a coordinate system that can be viewed as a Cartesian coordinate system where the axes have been placed so that they are not necessarily orthogonal to each other. See tensor.
* Affine differential geometry, a geometry that studies differential invariants under the action of the special affine group
* Affine gap penalty, the most widely used scoring function used for sequence alignment, especially in bioinformatics
* Affine geometry, a geometry characterized by parallel lines
* Affine group, the group of all invertible affine transformations from any affine space over a field K into itself
* Affine logic, a substructural logic whose proof theory rejects the structural rule of contraction
* Affine representation, a continuous group homomorphism whose values are automorphisms of an affine space
* Affine scheme, the spectrum of prime ideals of a commutative ring
   * Affine morphism, a morphism of schemes such that the pre-image of an open affine subscheme is affine
* Affine space, an abstract structure that generalises the affine-geometric properties of Euclidean space
* Affine tensor, a tensor belonging to an affine coordinate system
* Affine transformation, a transformation that preserves the relation of parallelism between lines
