The number of possible networks
Calculates the number of different directed acyclic graphs for a set of discrete and continuous nodes.
numbermixed(nd,nc)
nd |
an integer, which gives the number of discrete nodes. |
nc |
an integer, which gives the number of continuous nodes. |
No arrows are allowed from continuous nodes to discrete nodes. Cycles are not allowed. The number of networks is given by Bottcher (2003), using the result in Robinson (1977).
When nd+nc>15, the procedure is quite slow.
A numeric containing the number of directed acyclic graphs with the given node configuration.
Susanne Gammelgaard Bottcher,
Claus Dethlefsen rpackage.deal@gmail.com.
Bottcher, S.G. (2003). Learning Conditional Gaussian Networks. Aalborg University, 2003.
Robinson, R.W. (1977). Counting unlabeled acyclic digraphs, Lecture Notes in Mathematics, 622: Combinatorial Mathematics.
numbermixed(2,2) ## Not run: numbermixed(5,10)
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