VERTEX

Syntax: VERTEX number X_var [ Y_var [ Z_var [ angle ] ] ]

Retrieves the coordinates of the vertex specified using the number parameter. The coordinates and angle are stored in the specified variables. The angle variable contains the calculated slope in the specified point.

The vertex number can be specified either absolute or relative. If the vertex number is a floating point number in the interval 0-1, it is considered as a relative indexing where the number is threaded like a percentage of the total length of the element. The numbering of vertices starts with 1.

Example: VERTEX 0.5 x y results in the coordinates at the midpoint of the element.

If the number is an integer equal or larger to one, it is considered as an absolute indexing. Specifying an index larger than the number of vertices results in the last vertex. Use the NUMVERT variable to refer to the last vertex.

Example: VERTEX 5 x y stores the coordinates of the 5. vertex in the x,y variables.

Example: Traverse the vertices of a line string using the following loop statement: FOR (v = 1 ; v <=NUMVERT ; v = v+1) VERTEX v x y PLACE CIRCLE 1 x y END

Note: If the graphical element is not a linear element (TEXT, for example), the VERTEX command returns the coordinates of the elements origin. The value of the number parameter is not considered in this case but still must be specified; it is recommended to use the number zero.