The common origin of the two coordinate axes is called the origin of the plane rectangular coordinate system. X-axis and Y-axis divide the coordinate plane into four quadrants, the upper right part is called the first quadrant, and the other three parts are called the second quadrant, the third quadrant and the fourth quadrant in turn counterclockwise.
1, plane coordinate system characteristics:
The vertical axis and the horizontal axis of the plane coordinate system are just opposite, that is, the z axis and the y axis are interchanged.
Quadrants of plane coordinate system are sorted in reverse direction, and quadrants of measuring upper coordinate system are numbered clockwise.
Whether the origin of plane coordinate system has practical significance.
2. The difference between plane coordinate system and mathematical coordinate system:
The coordinate axes are different. The horizontal axis is the Y axis and the vertical axis is the X axis. Mathematically, the horizontal axis is the X axis and the vertical axis is the Y axis.
Quadrants are different. They are sorted clockwise in measurement and counterclockwise in mathematics. The upper right is the first quadrant.
In application, the plane rectangular coordinate system in measurement is the same as that in mathematics.
Extended data:
1, detailed plane coordinates:
In surveying and mapping, the Gaussian plane coordinate system takes the longitudinal axis as the X axis, indicating the north-south direction, and the north is positive; The horizontal axis is the Y axis, indicating the east-west direction, and the east is positive; Quadrants are arranged clockwise.
This is because the angle value of a point is calculated clockwise in the north direction when expressed in polar coordinates, but counterclockwise from the horizontal axis in analytic geometry.
2. Explain in detail the difference between measuring plane rectangular coordinate system and mathematical plane rectangular coordinate system:
The measuring coordinate system takes the north-south line passing through the origin, that is, the meridian, as the ordinate axis and the X axis; The east-west line passing through the origin is the abscissa axis, the abscissa axis is the X axis, and the ordinate axis is the Y axis.
The rectangular coordinate system is measured with the positive direction of the X axis as the starting edge, and the azimuth angle φ and I, II, III and IV quadrants are rotated clockwise (the mathematical coordinate system is measured with the positive direction of the X axis as the starting edge, and the inclination angle θ is rotated counterclockwise, which is divided into I, II, III and IV quadrants.
The coordinates (y, x) of the origin o of the measuring coordinate system are mostly two large positive integers, such as the coordinates of the origin of the local coordinate system in Beijing, y = 500,000m, x = 300,000m (the coordinates of the origin of mathematical coordinates, x=0, y=0).
Baidu Encyclopedia-Plane Cartesian Coordinate System