The Gauss map is a function from an oriented surface in Euclidean space to the unit sphere in . It associates to every point on the surface its oriented unit normal vector. Since the tangent space at a point on is parallel to the tangent space at its image point on the sphere, the differential can be considered as a map of the tangent space at into itself. The determinant of this map is the Gaussian curvature, and negative one-half of the trace is the mean curvature.
Another meaning of the Gauss map is the function
(Trott 2004, p. 44), where is the floor function, plotted above on the real line and in the complex plane.
The related function is plotted above, where is the fractional part.
The plots above show blowups of the absolute values of these functions (a version of the left figure appears in Trott 2004, p. 44).