PnodeStats {Peanut} | R Documentation |
These functions compute statistics of the marginal distribution of the
corresponding node. These are designed to be used with
Statistic
objects.
PnodeMargin(net, node) PnodeEAP(net, node) PnodeSD(net, node) PnodeMedian(net, node) PnodeMode(net, node)
net |
A |
node |
A |
These are the functions that implement the statistics. These are
typically called by calcStat
which finds the nodes
corresponding to the named nodes in the statistics. Both the net and
node are passes as arguments as this may be needed in some
implementations.
PnodeMargin
returns a vector corresponding to the states of
node
giving the marginal probabilities of the states.
PnodeEAP
returns a numeric scalar giving the expected a
posteriori value (mean) of the PnodeStateValues
of the
node. PnodeSD
gives the standard deviation.
PnodeMedian
assumes the states are ordered, and returns the
state at the 50th percentile. This is a factor (character) value.
PnodeMode
returns the most likely state as a factor (character)
value.
Russell Almond
Almond, R.G., Mislevy, R.J. Steinberg, L.S., Yan, D. and Willamson, D. M. (2015). Bayesian Networks in Educational Assessment. Springer. Chapter 13.
Statistics Class:
Statistic
Constructor function:
Statistic
These statistics will likely produce errors unless
PnetCompile
has been run first.
## Not run: library(PNetica) ## Need a specific implementation sess <- NeticaSession() startSession(sess) irt10.base <- ReadNetworks(paste(library(help="PNetica")$path, "testnets","IRT10.2PL.base.dne", sep=.Platform$file.sep),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) DeleteNetwork(irt10.base) stopSession(sess) ## End(Not run)