Download VisionWare Reference Guide, Version 3.0

vw.pt.line
Calling Sequence
CALL vw.pt.line (what, pt[], lin[ ], new[ ])
Function
Compute a new feature (as indicated by the what argument) based on a given point and line.
Usage Consideration
The input and output parameters are compatible with results of records in the point, line, and
vision-frame classes, as appropriate.
Input Parameters
what
Real value specifying what kind of new feature to compute using the
point and line. The possible values are:
0 Find the point on the line that is closest to the given point. Also return
the distance and angles of the lines involved (in the array new[ ]).
1 Compute the line, parallel to the given line, that goes through the
given point.
2 Compute the line, perpendicular to the given line, that goes through
the given point.
3 Compute a vision frame that has the line as the X-axis with the point
on the +Y-axis.
pt[ ]
Array of real values containing the coordinates for a point using the
standard representation. That is, the (x,y) location is (pt[vw.x],pt[vw.y]).
lin[ ]
Array of real values continuing the standard representation of a line:
lin[vw.x]
lin[vw.y]
lin[vw.ang]
lin[vw.cos]
lin[vw.sin]
X coordinate of a point on the line
Y coordinate of a point on the line
Angle of the line
Cosine of the angle
Sine of the angle
Output Parameter
new[ ]
Array of real values representing a new feature in the appropriate
standard representation depending on the what input parameter as
follows:
If what is 0: Nearest point and point-line distance.
new[vw.x]
new[vw.y]
new[vw.ang]
new[vw.cos]
new[vw.sin]
212
X coordinate of nearest point on line
Y coordinate of nearest point on line
Point-line distance
Angle of input line
Angle perpendicular to input line
VisionWare Reference Guide, Rev. A