In a DAG, CPDAG, MAG or PAG determine which nodes are possible descendants of x on definite status paths.

1 | ```
possibleDe(amat, x)
``` |

`amat` |
adjacency matrix of type amat.pag |

`x` |
(integer) position of node |

A non-endpoint vertex `X`

on a path `p`

in a partial mixed
graph is said to be of a *definite status* if it is either a collider or a
definite non-collider on `p`

. The path `p`

is said to be of a
*definite status* if all non-endpoint vertices on the path are of a
definite status (see e.g. Maathuis and Colombo (2015), Def. 3.4).

A possible descendent of x can be reached moving to adjacent nodes of x but never going against an arrowhead.

Vector with possible descendents.

Diego Colombo

M.H. Maathuis and D. Colombo (2015). A generalized back-door
criterion. *Annals of Statistics* **43** 1060-1088.

`backdoor`

, amatType

1 2 3 4 5 6 7 8 9 | ```
amat <- matrix( c(0,3,0,0,0,0, 2,0,2,0,0,0, 0,3,0,0,0,0, 0,0,0,0,1,0,
0,0,0,1,0,1, 0,0,0,0,1,0), 6,6)
colnames(amat) <- rownames(amat) <- letters[1:6]
if(require(Rgraphviz)) {
plotAG(amat)
}
possibleDe(amat, 1) ## a, b are poss. desc. of a
possibleDe(amat, 4) ## d, e, f are poss. desc. of d
``` |

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