13.13.3 Check if lines and/or planes in space are parallel: is_parallel
See section 12.16.11 for checking for parallels in
two-dimensional geometry.
The is_parallel command takes as arguments two lines, two
planes or a line and a plane.
is_parallel returns 1 is the objects are parallel;
it returns 0 otherwise.
Input:
L1 := line([0,0,0],[-1,-1,-1])
L2 := line([2,3,-2],[-1,-1,-1])
then:
is_parallel(L1,L2)
Output:
0
Input:
P := plane([-1,-1,-1],[1,2,-3],[0,0,0])
then:
is_parallel(P,L2)
Output:
1
Input:
P1 := plane([0,0,0],[1,2,-3],[1,1,-2])
P2 := plane([1,1,0],[2,3,-3],[2,2,-2])
then:
is_parallel(P1,P2)
Output:
1