|
<< Click to Display Table of Contents >> Navigation: Tutorials > Tutorial 5: Inference in an Influence Diagram > Tutorial5.R |
library(rSMILE)
source("License.R")
# Tutorial5 loads the XDSL file created by Tutorial4,
# then performs the series of inference calls,
# changing evidence each time.
indexToCoords = function(index, dimSizes) {
prod <- 1L
coords <- integer(length=length(dimSizes))
for (i in length(dimSizes):1) {
coords[i] <- floor(index / prod) %% dimSizes[[i]]
prod <- prod * dimSizes[[i]]
}
return(coords)
}
printGainMatrix = function(net, mtx, parents) {
#todo
dimCount <- 1 + length(parents)
dimSizes <- sapply(parents, function(x) net$getOutcomeCount(x))
dimSizes[length(dimSizes)+1] <- 1
for (elemIdx in 0:(length(mtx)-1)) {
coords <- indexToCoords(elemIdx, dimSizes)
cat(" Utility(");
if (dimCount > 1) {
parentIds <- sapply(parents, function(x) net$getNodeId(x))
outcomeIds <- sapply(1:length(parents),
function(x) net$getOutcomeId(parents[x], coords[x]))
cat(paste(parentIds, outcomeIds, sep="=", collapse=","))
}
cat(sprintf(")=%f\n", mtx[elemIdx+1]))
}
}
printFinancialGain = function(net) {
expectedUtility <- net$getNodeValue("Gain")
utilParents <- net$getValueIndexingParents("Gain")
printGainMatrix(net, expectedUtility, utilParents)
}
changeEvidenceAndUpdate = function(net, nodeId, outcomeId) {
if(!is.null(outcomeId)) {
net$setEvidence(nodeId, outcomeId)
} else {
net$clearEvidence(nodeId)
}
net$updateBeliefs()
printFinancialGain(net)
}
cat("Starting Tutorial5...\n")
net <- Network()
net$readFile("tutorial4.xdsl")
cat("No evidence set.\n")
net$updateBeliefs()
printFinancialGain(net)
cat("Setting Forecast=Good.\n")
changeEvidenceAndUpdate(net, "Forecast", "Good")
cat("Adding Economy=Up")
changeEvidenceAndUpdate(net, "Economy", "Up")
cat("Tutorial5 complete.\n")