R: Fitted Probabilities for PlackettLuce Objects

fitted.PlackettLuce {PlackettLuce}

R Documentation

Fitted Probabilities for PlackettLuce Objects

Description

Fitted probabilities for all choice/alternative combinations in the data.

Usage

## S3 method for class 'PlackettLuce'
fitted(object, aggregate = TRUE, free = TRUE, ...)

## S3 method for class 'pltree'
fitted(object, aggregate = TRUE, free = TRUE, ...)

Arguments

`object`	an object as returned by `PlackettLuce` or `pltree`.
`aggregate`	logical; if `TRUE` observations of the same choice from the same set of alternatives are aggregated.
`free`	logical; if `TRUE` only free choices are included, i.e. choices of one item from a set of one item are excluded.
`...`	further arguments, currently ignored.

Value

A list with the following components

`choices`	The selected item(s).
`alternatives`	The set of item(s) that the choice was made from.
`ranking`	The ranking(s) including this choice.
`n`	The weighted count of rankings including this choice (equal to the ranking weight if `aggregate = FALSE`.
`fitted`	The fitted probability of making this choice.

If object was a "pltree" object, the list has an additional element, node, specifying which node the ranking corresponds to.

Examples

R <- matrix(c(1, 2, 0, 0,
              4, 1, 2, 3,
              2, 1, 1, 1,
              1, 2, 3, 0,
              2, 1, 1, 0,
              1, 0, 3, 2), nrow = 6, byrow = TRUE)
colnames(R) <- c("apple", "banana", "orange", "pear")

mod <- PlackettLuce(R)
fit <- fitted(mod)
fit