isADMG {ggm} | R Documentation |
Acyclic directed mixed graphs
Description
Check if it is an adjacency matrix of an ADMG
Usage
isADMG(amat)
Arguments
amat |
An adjacency matrix. |
Details
Checks if the following conditions must hold: (i) no undirected edge meets an arrowhead; (ii) no directed cycles;
Value
A logical value, TRUE
if it is an ancestral graph and FALSE
otherwise.
Author(s)
Giovanni M. Marchetti, Mathias Drton
References
Richardson, T. S. and Spirtes, P. (2002). Ancestral Graph Markov Models. Annals of Statistics, 30(4), 962–1030.
See Also
Examples
## Examples from Richardson and Spirtes (2002)
a1 <- makeMG(dg=DAG(a~b, b~d, d~c), bg=UG(~a*c))
isADMG(a1) # Not an AG. (a2) p.969
a2 <- makeMG(dg=DAG(b ~ a, d~c), bg=UG(~a*c+c*b+b*d)) # Fig. 3 (b1) p.969
isADMG(a2)
[Package ggm version 2.5.1 Index]