querygrain: Query a network
In DataSciBurgoon/gRain: Graphical Independence Networks

Description Usage Arguments Value Note Author(s) References See Also Examples

Query an independence network, i.e. obtain the conditional distribution of a set of variables - possibly (and typically) given finding (evidence) on other variables.

querygrain(
  object,
  nodes = nodeNames(object),
  type = "marginal",
  evidence = NULL,
  exclude = TRUE,
  normalize = TRUE,
  result = "array",
  details = 0
)

`object`	A `grain` object.
`nodes`	A vector of nodes; those nodes for which the (conditional) distribution is requested.
`type`	Valid choices are `"marginal"` which gives the marginal distribution for each node in `nodes`; `"joint"` which gives the joint distribution for `nodes` and `"conditional"` which gives the conditional distribution for the first variable in `nodes` given the other variables in `nodes`.
`evidence`	An alternative way of specifying findings (evidence), see examples below.
`exclude`	If `TRUE` then nodes on which evidence is given will be excluded from `nodes` (see above).
`normalize`	Should the results be normalized to sum to one.
`result`	If "data.frame" the result is returned as a data frame (or possibly as a list of dataframes).
`details`	Debugging information

A list of tables with potentials.

setEvidence() is an improvement of setFinding() (and as such setFinding is obsolete). Users are recommended to use setEvidence() in the future.

setEvidence() allows to specification of "hard evidence" (specific values for variables) and likelihood evidence (also known as virtual evidence) for variables.

The syntax of setEvidence() may change in the future.

Søren Højsgaard, sorenh@math.aau.dk

Søren Højsgaard (2012). Graphical Independence Networks with the gRain Package for R. Journal of Statistical Software, 46(10), 1-26. http://www.jstatsoft.org/v46/i10/.

setEvidence, getEvidence, retractEvidence, pEvidence

testfile <- system.file("huginex", "chest_clinic.net", package = "gRain")
chest <- loadHuginNet(testfile, details=0)
qb <- querygrain(chest)
qb

lapply(qb, as.numeric) # Safe
sapply(qb, as.numeric) # Risky