## Interfacing with the **pcalg** R package

The **pcalg** package (link) is a versatile
R package for structure learning. It implements both score-based algorithms such as the *Greedy Equivalent Search*
(GES) and constraint-based algorithms such as the *PC*. It is one of the few R packages that can handle discrete
data sets as well as continuous data sets.

### Exporting a network structure to **pcalg**

Exporting `bn`

or `bn.fit`

objects to **pcalg** is not currently implemented in
**bnlearn**.

### Importing a network structure from **pcalg**

Importing network structures is implementeed in `as.bn()`

.

> library(pcalg) > data("gmG") > suffStat = list(C = cor(gmG8$x), n = nrow(gmG8$x)) > pc.gmG = pc(suffStat, indepTest = gaussCItest, p = ncol(gmG8$x), alpha = 0.01) > library(bnlearn) > as.bn(pc.gmG)

Random/Generated Bayesian network model: [partially directed graph] nodes: 8 arcs: 8 undirected arcs: 2 directed arcs: 6 average markov blanket size: 2.25 average neighbourhood size: 2.00 average branching factor: 0.75 generation algorithm: Empty

Importing fitted Bayesian networks into `bn.fit`

objects is not supported. Note that as graphs are imported
with `as.bn()`

they are checked to be acyclic, unless the user specifies `check.cycles = FALSE`

.

`Wed Nov 9 16:45:33 2022`

with **bnlearn**

`4.9-20221107`

and `R version 4.2.2 (2022-10-31)`

.