querygrain {gRain} | R Documentation |
Query a network
Description
Query an independence network, i.e. obtain the conditional distribution of a set of variables - possibly (and typically) given finding (evidence) on other variables.
Usage
querygrain(
object,
nodes = nodeNames(object),
type = "marginal",
evidence = NULL,
exclude = TRUE,
normalize = TRUE,
simplify = FALSE,
result = "array",
details = 0
)
Arguments
object |
A |
nodes |
A vector of nodes; those nodes for which the (conditional) distribution is requested. |
type |
Valid choices are |
evidence |
An alternative way of specifying findings (evidence), see examples below. |
exclude |
If |
normalize |
Should the results be normalized to sum to one. |
simplify |
Should the result be simplified (to a dataframe) if possible. |
result |
If "data.frame" the result is returned as a data frame (or possibly as a list of dataframes). |
details |
Debugging information |
Value
A list of tables with potentials.
Note
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is obsolete).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.
Author(s)
Søren Højsgaard, sorenh@math.aau.dk
References
Søren Højsgaard (2012). Graphical Independence Networks with the gRain Package for R. Journal of Statistical Software, 46(10), 1-26. https://www.jstatsoft.org/v46/i10/.
See Also
setEvidence
, getEvidence
,
retractEvidence
, pEvidence
Examples
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