brief introduction
Coordinate zubi ā o, mathematically, the essence of coordinates is ordered number pairs; The concept of plane is used to represent the absolute position of a point; Extend to the plane position of the game to represent the game things.
Geographically defined coordinates, that is, geographical coordinate system, use three-dimensional spherical surface to define the position of the earth's surface, so as to realize the reference of points on the earth's surface through latitude and longitude. A geographical coordinate system consists of three parts: angle measurement unit, prime meridian and reference ellipsoid.
The position of a point can be described by a set of numbers (ordered array). For example, on the plane, two intersecting straight lines l 1 and L2 can be drawn; Passing through any point m on the plane, make two straight lines parallel to l 1 and l2 respectively, and intersect with l2 and l 1 at P2 and P1; In this way, point M can be represented by its directed distances P2M and P 1M from l 1 to l2 and l 1.
These two directed distances are called coordinates of point M, two straight lines are called coordinate axes, and the intersection of coordinate axes is called origin. When two straight lines are perpendicular to each other, it is a plane rectangular coordinate system.
In space, three intersecting planes can be made, and any point m in space can be represented by the directed distance from one of the intersecting lines passing through this point and parallel to the other plane. These three directed distances are the coordinates of a point m in space, three planes are called coordinate planes, and the intersection of any two coordinate planes is the coordinate axis. The intersection of the three axes is the origin.
In apollonius's conic theory, the term "coordinate line" has always been used. Descartes and Fermat used the datum line with the origin many times, and Leibniz called the vertical and horizontal datum line coordinates.
Above content reference: Baidu Encyclopedia-Coordinates