gRaven (version 1.1.10)

get.normalization.constant: Get the normalisation constant of a gRaven domain

Description

Get the normalisation constant of a gRaven domain

Usage

get.normalization.constant(domain, log = FALSE)

Value

numeric, the value of the normalisation constant (or its logarithm). If no evidence has been entered, the constant is defined as 1.

Arguments

domain

name of a gRaven domain

log

logical, should constant be returned on log scale?

Author

Peter J. Green,

Examples

yn <- c("yes","no")
chest<-hugin.domain()

add.node(chest,"asia",states=yn)
add.node(chest,"tub",states=yn)
add.node(chest,"smoke",states=yn)
add.node(chest,"lung",states=yn)
add.node(chest,"bronc",states=yn)
add.node(chest,"either",states=yn)
add.node(chest,"xray",states=yn)
add.node(chest,"dysp",states=yn)

add.edge(chest,"tub","asia")
add.edge(chest,"lung","smoke")
add.edge(chest,"bronc","smoke")
add.edge(chest,"either","lung")
add.edge(chest,"either","tub")
add.edge(chest,"xray","either")
add.edge(chest,"dysp","bronc")
add.edge(chest,"dysp","either")

set.table(chest,"asia",c(0.01,0.99))
set.table(chest,"tub",c(0.05,0.95,0.01,0.99))
set.table(chest,"smoke",c(0.5,0.5))
set.table(chest,"lung",c(0.1,0.9,0.01,0.99))
set.table(chest,"bronc",c(0.6,0.4,0.3,0.7))
set.table(chest,"either",c(1,0,1,0,1,0,0,1))
set.table(chest,"xray",c(0.98,0.02,0.05,0.95))
set.table(chest,"dysp",c(0.9,0.1,0.7,0.3,0.8,0.2,0.1,0.9))

compile(chest)
get.normalization.constant(chest)

set.finding(chest,"asia","yes")
set.finding(chest,"dysp","yes")
get.normalization.constant(chest)