finding: Set, retrieve, and retract finding in Bayesian network.

In gRain: Bayesian Networks

Set, retrieve, and retract finding in Bayesian network.

Description

Set, retrieve, and retract finding in Bayesian network. NOTICE: The functions described here are kept only for backward compatibility; please use the corresponding evidence-functions in the future.

Usage

setFinding(object, nodes = NULL, states = NULL, flist = NULL, propagate = TRUE)

Arguments

object	A "grain" object
nodes	A vector of nodes
states	A vector of states (of the nodes given by 'nodes')
flist	An alternative way of specifying findings, see examples below.
propagate	Should the network be propagated?

Note

NOTICE: The functions described here are kept only for backward compatibility; please use the corresponding evidence-functions in the future:

setEvidence() is an improvement of setFinding() (and as such setFinding is obsolete).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, [e-mail]

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, querygrain

Examples

## setFindings
yn <- c("yes", "no")
a    <- cpt(~asia, values=c(1, 99),levels=yn)
t.a  <- cpt(~tub+asia, values=c(5, 95, 1, 99),levels=yn)
s    <- cpt(~smoke, values=c(5,5), levels=yn)
l.s  <- cpt(~lung+smoke, values=c(1, 9, 1, 99), levels=yn)
b.s  <- cpt(~bronc+smoke, values=c(6, 4, 3, 7), levels=yn)
e.lt <- cpt(~either+lung+tub,values=c(1, 0, 1, 0, 1, 0, 0, 1),levels=yn)
x.e  <- cpt(~xray+either, values=c(98, 2, 5, 95), levels=yn)
d.be <- cpt(~dysp+bronc+either, values=c(9, 1, 7, 3, 8, 2, 1, 9), levels=yn)
chest.cpt <- compileCPT(a, t.a, s, l.s, b.s, e.lt, x.e, d.be)
chest.bn <- grain(chest.cpt)

## These two forms are equivalent
bn1 <- setFinding(chest.bn, nodes=c("chest", "xray"), states=c("yes", "yes"))
bn2 <- setFinding(chest.bn, flist=list(c("chest", "yes"), c("xray", "yes")))

getFinding(bn1)
getFinding(bn2)

pFinding(bn1)
pFinding(bn2)

bn1 <- retractFinding(bn1, nodes="asia")
bn2 <- retractFinding(bn2, nodes="asia")

getFinding(bn1)
getFinding(bn2)

pFinding(bn1)
pFinding(bn2)

gRain documentation built on Oct. 18, 2024, 1:07 a.m.