Check if a 3-node-path is Legal
Check if the path a-b-c is legal.
A 3-node path a-b-c is “legal” iff either b is a collider or a-b-c is a triangle.
legal.path(a, b, c, amat)
a,b,c |
(integer) positions in adjacency matrix of nodes a, b, and c, respectively. |
amat |
Adjacency matrix (coding 0,1,2,3 for no edge, circle,
arrowhead, tail; e.g., |
TRUE if path is legal, otherwise FALSE.
Prerequisite: a-b-c must be in a path (and
this is not checked by legal.path()).
Markus Kalisch (kalisch@stat.math.ethz.ch)
amat <- matrix( c(0,1,1,0,0, 2,0,1,0,0, 2,2,0,2,1,
0,0,1,0,0, 0,0,2,0,0), 5,5)
legal.path(1,3,5, amat)
legal.path(1,2,3, amat)
legal.path(2,3,4, amat)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.