uscale: Utility Scale of an EBA Choice Model
In eba: Elimination-by-Aspects Models

Description Usage Arguments Details Value See Also Examples

Extract the (normalized) utility scale for an elimination-by-aspects (EBA) model.

1	uscale(object, norm = "sum", log = FALSE)

`object`	an object of class `eba`, typically the result of a call to `eba`
`norm`	either `sum`, so the scale values sum to unity (default); or a number from 1 to number of stimuli, so this scale value becomes one; or `NULL` (no normalization)
`log`	should the log of the utility scale values be returned? Defaults to FALSE.

Each utility scale value is defined as the sum of aspect values (EBA model parameters) that characterize a given stimulus. First these sums are computed for all stimuli, then normalization (if any) is applied. As each type of normalization corresponds to a multiplication by a positive real number, the ratio between scale values remains constant.

The (normalized) utility scale of the stimuli.

eba, cov.u, wald.test.

data(drugrisk)
A <- list(c(1), c(2,7), c(3,7), c(4,7,8), c(5,7,8), c(6,7,8))
eba1 <- eba(drugrisk[, , group = "male30"], A)  # EBA model

uscale(eba1)                    # sum-to-unity normalization
uscale(eba1, norm=1)            # u(alcohol) := 1
uscale(eba1, norm=5)            # u(heroine) := 1
uscale(eba1, norm=NULL)         # no normalization
uscale(eba1, norm=1, log=TRUE)  # log utility scale, log u(alcohol) := 0