横坐标 定义
In mathematics, the abscissa and the ordinate are respectively the first and second coordinates of a point in a coordinate system. The abscissa is the first coordinate in an ordered pair and the ordinate is the second coordinate. For instance with the point (3, 2) the abscissa is 3 and the ordinate is 2.
概述
The abscissa of a point is the signed measure of its projection on the primary axis, whose absolute value is the distance between the projection and the origin of the axis, and whose sign is given by the location on the projection relative to the origin (before: negative; after: positive).
点的纵坐标是其在次轴上的投影的有符号度量，其绝对值是投影与轴原点之间的距离，其符号由投影上相对于原点的位置给出（之前：负；之后：正）。
通常这些是二维矩形笛卡尔坐标系统中一个点的水平和垂直坐标。这些术语也可以分别指代二维 graph 的水平轴和垂直轴（通常是 x 轴和 y 轴）。有序对由两个项组成：横坐标（水平，通常是 x）和纵坐标（垂直，通常是 y），它们定义了一个点在二维矩形空间中的位置。
来源
“Abscissa and Ordinate.” Wikipedia, Wikimedia Foundation, 6 Feb. 2020, en.wikipedia.org/wiki/Abscissa_and_ordinate.