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Causal Inference: The R package pcalg

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16 <strong>Causal</strong> Graphical Models: Package <strong>pcalg</strong><br />

1 2<br />

3 4<br />

5<br />

2 3<br />

●<br />

4<br />

●<br />

●<br />

●<br />

5<br />

●<br />

●<br />

Figure 5: True underlying DAG (left) and estimated PAG (right), when applying the FCI<br />

and RFCI algorithms to the data set gmL. <strong>The</strong> output of FCI and RFCI is identical. Variable<br />

V 1 of the true underlying DAG is latent.<br />

D-SEP sets and thus does not make tests conditioning on them. This makes rfci() much<br />

faster than fci(). <strong>The</strong> orientation rule for v-structures and the orientation rule for so-called<br />

discriminating paths (rule 4) were modified in order to produce a PAG which, in the oracle<br />

version, is guaranteed to have correct ancestral relationships.<br />

<strong>The</strong> function can be called in the following way:<br />

rfci(suffStat, indepTest, p, alpha, verbose = FALSE, fixedGaps = NULL,<br />

fixedEdges = NULL, NAdelete = TRUE, m.max = Inf)<br />

where the arguments suffStat, indepTest, p, alpha, fixedGaps, fixedEdges, NAdelete<br />

and m.max are identical to those in skeleton().<br />

As an example, we re-run the example from Section 3.3 and show the PAG estimated with<br />

rfci() in Figure 5. <strong>The</strong> PAG estimated with fci() and the PAG estimated with rfci() are<br />

the same.<br />

R> data("gmL")<br />

R> suffStat1 pag.est

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