1、X: The distance from the origin to the centroid, as measured along the x-axis.Y: The distance from the origin to the centroid, as measured along the y-axis.Z: The distance from the origin to the centroid, as measured along the z-axis.If measured in a Cylindrical coordinate system, the coordinates of
2、 the planeR: The distance from the z-axis of the coordinate system to the centroid, as measured within a plane which contains the centroid and is orthogonal to the z-axis of the coordinate system.A: The direction, measured as an angle, between a reference radius vector and a radius vector that conta
3、ins the centroid and is projected onto the xy-plane. The reference radius vector may be considered to be the x-axis. The height from the origin to the centroid in the cylindrical coordinate system, as measured along the z-axis.The other attributes of the plane feature are:Angle: The angle between th
4、e projection of the planes normal vector onto the xy-plane and the x-axis of the current coordinate system.X-angle: The angle between the planes normal vector and the x-axis of the current coordinate system. （X-Angle = arc cosine k）. The x-angle is a positive number between 0 and 180 degrees.Y-angle
5、: The angle between the planes normal vector and the y-axis of the current coordinate system. （Y-Angle = arc cosine l）. The y-angle is a positive number between 0 and 180 degrees.Z-angle: The angle between the planes normal vector and the z-axis of the current coordinate system. （Z-Angle = arc cosin
6、e m）. The z-angle is a positive number between 0 and 180 degrees.Flatness: Flatness is a condition for which an element of a surface is in a plane.Flatness is reported as the width of the zone formed by two closest parallel planes that fully contain the point set used to fit the plane feature. A val
7、ue of zero indicates perfect flatness.Flatness （minimum）: The distance from the fitted plane to the measured point farthest below the fitted plain in the point set. Above and below are determined by the direction of the plane vector. See Explanation of Max/Min distance in different cases.Flatness （m
8、aximum）: The distance from the fitted plane to the measured point farthest above the fitted plain in the point set. Above and below are determined by the direction of the plane vector. See Explanation of Max/Min distance in different cases.Parallelism: The condition of a feature, projected to a cert
9、ain plane, being equidistant at all elements from a datum （reference）. Quantitatively, parallelism is defined as the absolute distant difference between the farthest and closest points from the datum.Parallelism is evaluated relative to a reference line or xy-plane. When evaluating a set of points w
10、ith a reference line, parallelism uses the projections of the points and reference line onto the xy-plane in the current coordinate system, or z/ref plane feature, and is specified as a zone tolerance. The z/ref plane feature is a plane including the reference line and parallel to （or including） the
11、 z-axis. When evaluating a set of points with a xy-plane, parallelism is calculated in three-dimensional space.Parallelism （minimum）: The distance from the referenced line or plane to the point in the point set with the least value （least positive value if all evaluated points are positive, or most
12、negative value if evaluated points include negative values）. See Explanation of Max/Min distance in different cases.Parallelism （maximum）: The distance from the reference line or plane to the point in the point set with the greatest value （most positive value if evaluated points include positive val
13、ues, or least negative value if all evaluated points are negative）. See Explanation of Max/Min distance in different cases.平面相关知识：算法如下：VB源代码：Option ExplicitPublic Const PI = 3.1415926535897Public Type tagPoint x As Double y As Double z As DoubleEnd TypePublic Type tagLine2D k As Double Slope ,K is t
14、he K of y=kx+b b As Doubleintercept,B isB Angle As Doublearctg（k）0 to 180 deg Straightness As Double RSQ As DoublePublic Type tagLine3D3D lines formula is showing as following.1）|Ax +By +Z+D =0 |A1x+B1y+z+D1=02）（x-x0）/m=（y-y0）/n=（z-z0）/p-（x-x0）/m=（y-y0）/n=z/13）x=mt+x0,y=nt+y0,z=pt+z0Only points coordinate is （a+b*Z, c+d*Z,Z）,so the
