Arguments

vectorlist  list of (minimum 2) sequence items, which specifies a line segment;
each line sequence has the format :

matrix  (optional) transformation matrix (4 x 4 double), list of 4 sub-list of each 4 numbers (integer or double);
the transformation matrix os applied to all specified 2d/3d points

Return

always NIL

Example

(grvecs  2  '(0 0)  '(10 10)  4  '(10 10)  '(20 0))  draw a yellow line [0,0] - [10,10], and a cyan line [10,10] . [20, 0]

Remarks

see (grarc) and (grfill) functions (specific for BricsCAD)