If two geometries are parallel they have the same orientation. euclid allows
assessing parallelity of a broad range of geometries. If x and y are
surfaces the parallelity of their supporting plane is returned. If x and
y are curves, the parallelity of their supporting line is returned. If it
is a mix of surface and curve, the parallelity is calculated as whether the
supporting plane and supporting line intersects at a point.
See also
Other Predicates:
collinear(),
constant_in,
geometry_class,
geometry_turns,
has_intersection(),
in_order(),
is_degenerate(),
location_predicates
Examples
# Are two triangles parallel (only meaningful in 3D)
p <- point(sample(20, 6), sample(20, 6), sample(20, 6))
t1 <- triangle(p[1], p[2], p[3])
t2 <- triangle(p[4], p[5], p[6])
parallel(t1, t2)
#> [1] FALSE
# Same as:
parallel(as_plane(t1), as_plane(t2))
#> [1] FALSE
# Parallelity of surface and curve
parallel(t1, line(p[5], p[6]))
#> [1] FALSE