PnetCompile: Compiles a Parameterized Bayesian Network

In ralmond/Peanut: Parameterized Bayesian Networks, Abstract Classes

Compiles a Parameterized Bayesian Network

Description

This function requests that the Bayes net be compiled—transformed so that inference can be carried out.

Usage

PnetCompile(net)

Arguments

net	A Pnet object to be compiled.

Details

Many Bayesian network algorithm have two phases. The graph is built as an acyclic directed graph. Before inference is carried out, the graph is transformed into a structure called a Junction Tree, Tree of Cliques or Markov Tree (Almond, 1995).

This function requests that implementation specific processing, particularly, building the appropriate Markov Tree, be done for the net, so that it can be placed in inference mode instead of editing mode.

Value

The compile net argument should be returned.

Note

It should be harmless to call this function on a net which is already compiled.

Author(s)

Russell Almond

References

Almond, R. G. (1995). Graphical Belief Models. Chapman and Hall.

See Also

The following functions will likely return errors if the net is not compiled: PnodeEvidence, calcStat, PnodeMargin, PnodeEAP, PnodeSD, PnodeMedian, PnodeMode.

Examples

## Not run: 

library(PNetica) ## Need a specific implementation
sess <- NeticaSession()
startSession(sess)

irt10.base <- ReadNetworks(system.file("testnets", "IRT10.2PL.base.dne",
                           package="PNetica"),session=sess)
irt10.base <- as.Pnet(irt10.base)  ## Flag as Pnet, fields already set.
irt10.theta <- PnetFindNode(irt10.base,"theta")
irt10.items <- PnetPnodes(irt10.base)
## Flag items as Pnodes
for (i in 1:length(irt10.items)) {
  irt10.items[[i]] <- as.Pnode(irt10.items[[i]])
  
}
## Make some statistics
marginTheta <- Statistic("PnodeMargin","theta","Pr(theta)")
meanTheta <- Statistic("PnodeEAP","theta","EAP(theta)")
sdTheta <- Statistic("PnodeSD","theta","SD(theta)")
medianTheta <- Statistic("PnodeMedian","theta","Median(theta)")
modeTheta <- Statistic("PnodeMedian","theta","Mode(theta)")


BuildAllTables(irt10.base)
PnetCompile(irt10.base) ## Netica requirement

calcStat(marginTheta,irt10.base)
calcStat(meanTheta,irt10.base)
calcStat(sdTheta,irt10.base)
calcStat(medianTheta,irt10.base)
calcStat(modeTheta,irt10.base)

PnodeEvidence(irt10.items[[1]]) <- "Correct"

calcStat(marginTheta,irt10.base)
calcStat(meanTheta,irt10.base)
calcStat(sdTheta,irt10.base)
calcStat(medianTheta,irt10.base)
calcStat(modeTheta,irt10.base)


DeleteNetwork(irt10.base)
stopSession(sess)

## End(Not run)

ralmond/Peanut documentation built on Sept. 19, 2023, 8:27 a.m.