point at infinity

名词 n.
中文释义

英文释义

名词 n.
  1. An asymptotic point in 3-dimensional space, viewed from some point, at which parallel lines appear to meet and which in perspective drawing is represented as a vanishing point.
    — The point where a family of parallels appear to meet is called their “vanishing point” by artists, and their point at infinity by mathematicians. The horizon itself, which consists of all the points at infinity, is called the line at infinity.
  2. Any point added to a space to achieve projective completion.
    — 1960, Roger A. Johnson, Advanced Euclidean Geometry, Republished 2007, page 45, In the geometry of inversion, therefore, it is usual to sacrifice the line of points at infinity which is so useful in other fields, and adopt the convention of a single point at infinity, the inverse of the center of the circle of inversion.
  3. An ideal point. excessive
    — Hyperbolic geometry provides each line with two points at infinity. Whether there is a piece of the line beyond the points at infinity, completing the piece lying in the finite to a closed curve, we cannot say, since we cannot move as far as the points at infinity, let alone beyond them.

词形变化

points at infinity plural
0 次浏览 数据来源: Wiktionary