Affine distance
From Encyclopedia of Mathematics
An invariant determined by two line elements in an equi-affine plane. A point 
together with a straight line 
passing through it is called a line element 
. For two line elements 
and 
the affine distance is 
, where 
is the surface area of the triangle 
and 
is the point of intersection of the straight lines 
and 
. The affine distance for two elements tangent to a parabola is equal to the affine arc length of this parabola (cf. Affine parameter). In the three-dimensional equi-affine space the affine distance may also be defined in terms of elements consisting of pairwise incident points, straight lines and planes.
How to Cite This Entry:
Affine distance. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Affine_distance&oldid=15884
Affine distance. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Affine_distance&oldid=15884
This article was adapted from an original article by A.P. Shirokov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article