General tools for alignment. Any boundable object with a local origin can be aligned; this includes diagrams, of course, but it also includes paths.
align v aligns a boundable object along the edge in the
v. That is, it moves the local origin in the
v until it is on the boundary. (Note that if the
local origin is outside the boundary to begin, it may have to
align v d a moves the origin of
a to a distance of
the center along
r is the radius along
align v 0 centers along
align v 1 moves the origin
in the direction of
v to the very edge of the bounding region.