logical: Conditional probability tables based on logical dependencies

In gRain: Bayesian Networks

Conditional probability tables based on logical dependencies

Description

Generate conditional probability tables based on the logical expressions AND and OR.

Usage

booltab(vpa, levels = c(TRUE, FALSE), op = `&`)

andtab(vpa, levels = c(TRUE, FALSE))

ortab(vpa, levels = c(TRUE, FALSE))

andtable(vpa, levels = c(TRUE, FALSE))

ortable(vpa, levels = c(TRUE, FALSE))

Arguments

vpa	Node and two parents; as a formula or a character vector.
levels	The levels (or rather labels) of v, see 'examples' below.
op	A logical operator.

Details

Regarding the form of the argument vpa: To specify P(a|b,c) one may write ~a|b+c or ~a+b+c or ~a|b:c or ~a:b:c or c("a","b","c"). Internally, the last form is used. Notice that the + and : operator are used as separators only. The order of the variables is important so + and : DO NOT commute.

Value

An array.

Note

andtable and ortable are aliases for andtab and ortab and are kept for backward compatibility.

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

cptable

Examples

## Logical OR:

## A variable v is TRUE if either of its parents pa1 and pa2 are TRUE:
ortab( c("v", "pa1", "pa2") ) |> ftable(row.vars="v")
## TRUE and FALSE can be recoded to e.g. yes and no:
ortab( c("v", "pa1", "pa2"), levels=c("yes", "no") ) |> ftable(row.vars="v")

## Logical AND:

## Same story here:
andtab(c("v", "pa1", "pa2") ) |> ftable(row.vars="v")
andtab(c("v", "pa1", "pa2"), levels=c("yes", "no") ) |> ftable(row.vars="v")

## Combined approach

booltab(c("v", "pa1", "pa2"), op=`&`) |> ftable(row.vars="v") ## AND
booltab(c("v", "pa1", "pa2"), op=`|`) |> ftable(row.vars="v") ## OR

booltab(~v + pa1 + pa2, op=`&`) |> ftable(row.vars="v") ## AND
booltab(~v + pa1 + pa2, op=`|`) |> ftable(row.vars="v") ## OR

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