Conditional probability tables based on logical dependencies

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

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.

Value

An array.

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.

Note

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

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

Author

Søren Højsgaard, sorenh@math.aau.dk

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")
#>       pa1 TRUE       FALSE      
#>       pa2 TRUE FALSE  TRUE FALSE
#> v                               
#> TRUE         1     1     1     0
#> FALSE        0     0     0     1
## 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")
#>     pa1 yes     no   
#>     pa2 yes no yes no
#> v                    
#> yes       1  1   1  0
#> no        0  0   0  1

## Logical AND:

## Same story here:
andtab(c("v", "pa1", "pa2") ) |> ftable(row.vars="v")
#>       pa1 TRUE       FALSE      
#>       pa2 TRUE FALSE  TRUE FALSE
#> v                               
#> TRUE         1     0     0     0
#> FALSE        0     1     1     1
andtab(c("v", "pa1", "pa2"), levels=c("yes", "no") ) |> ftable(row.vars="v")
#>     pa1 yes     no   
#>     pa2 yes no yes no
#> v                    
#> yes       1  0   0  0
#> no        0  1   1  1

## Combined approach

booltab(c("v", "pa1", "pa2"), op=`&`) |> ftable(row.vars="v") ## AND
#>       pa1 TRUE       FALSE      
#>       pa2 TRUE FALSE  TRUE FALSE
#> v                               
#> TRUE         1     0     0     0
#> FALSE        0     1     1     1
booltab(c("v", "pa1", "pa2"), op=`|`) |> ftable(row.vars="v") ## OR
#>       pa1 TRUE       FALSE      
#>       pa2 TRUE FALSE  TRUE FALSE
#> v                               
#> TRUE         1     1     1     0
#> FALSE        0     0     0     1

booltab(~v + pa1 + pa2, op=`&`) |> ftable(row.vars="v") ## AND
#>       pa1 TRUE       FALSE      
#>       pa2 TRUE FALSE  TRUE FALSE
#> v                               
#> TRUE         1     0     0     0
#> FALSE        0     1     1     1
booltab(~v + pa1 + pa2, op=`|`) |> ftable(row.vars="v") ## OR
#>       pa1 TRUE       FALSE      
#>       pa2 TRUE FALSE  TRUE FALSE
#> v                               
#> TRUE         1     1     1     0
#> FALSE        0     0     0     1