pcalg: possAn – R documentation

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possAn

Find possible ancestors of given node(s).

Description

In a DAG, CPDAG, MAG or PAG determine which nodes are (possible) ancestors of x on definite status or just any paths potentially avoiding given nodes on the paths.

Usage

possAn(m, x, y = NULL, possible = TRUE, ds = TRUE,
type = c("cpdag", "pdag", "dag", "mag", "pag"))

Arguments

`m`	Adjacency matrix in coding according to type.
`x`	Node positions of starting nodes.
`y`	Node positions of nodes through which a path must not go.
`possible`	If `TRUE`, possible ancestors are returned.
`ds`	If `TRUE`, only paths of definite status are considered.
`type`	Type of adjacency matrix in `m`. The coding is according to `amatType`.

Details

Not all possible combinations of the arguments are currently implemented and will issue an error if called.

Value

Vector of all node positions found as (possible) ancestors of the nodes in x.

Author(s)

Markus Kalisch

Examples

## a -- b -> c
amat <- matrix(c(0,1,0, 1,0,1, 0,0,0), 3,3)
colnames(amat) <- rownames(amat) <- letters[1:3]
plot(as(t(amat), "graphNEL"))

possAn(m = amat, x = 3, possible = TRUE, ds = FALSE, type = "pdag") ## all nodes
possAn(m = amat, x = 3, y = 2, possible = TRUE, ds = FALSE, type = "pdag") ## only node 1

pcalg

Methods for Graphical Models and Causal Inference

v2.7-2

GPL (>= 2)

Authors

Markus Kalisch [aut, cre], Alain Hauser [aut], Martin Maechler [aut], Diego Colombo [ctb], Doris Entner [ctb], Patrik Hoyer [ctb], Antti Hyttinen [ctb], Jonas Peters [ctb], Nicoletta Andri [ctb], Emilija Perkovic [ctb], Preetam Nandy [ctb], Philipp Ruetimann [ctb], Daniel Stekhoven [ctb], Manuel Schuerch [ctb], Marco Eigenmann [ctb], Leonard Henckel [ctb], Joris Mooij [ctb]

Initial release

2021-4-20