patt.worth {prefmod}

Function to calculate and print worth parameters from pattern model results

Description

Worth parameter are calculated from the results of a pattern model fit, i.e., from pattPC.fit, pattR.fit, pattL.fit, and pattLrep.fit or from a gnm-fit, respectively. For the latter, the function only works if the design matrix had been generated using patt.design.

Usage

patt.worth(fitobj, obj.names = NULL, outmat = "worth")

Arguments

fitobj

Object of class pattMod obtained from pattern model fit.

obj.names

names for the objects, for repeated measurement models just the names of objects for the first time point

outmat

a matrix of estimated worth parameters (outmat = "worth", the default) or pattern model parameters (outmat = "lambda").

Details

If the pattern model includes categorical subject covariates, the function provides estimates for all groups formed by the full crossclassification. Numerical subject covariates are not implemented (yet)(see Warning below).

Value

patt.worth returns a matrix of worth or model parameters. If subject covariates have been specified, each column represents a groups defined by the crossclassification of the subject covariates.

The function plot gives a plot of the estimates.

Warning

If the pattern model has been fitted including numerical subject covariates, they are ignored. However, estimates for the remaining predictors are calculated for convenience. Please note, that these cannot be interpreted as standard estimates but are intercepts of the regression model where the objects (or reparameterised objects) are explained by one or more numerical subject covariates.

Author(s)

Reinhold Hatzinger

See Also

pattPC.fit, pattR.fit, pattL.fit, pattLrep.fit, plot

Examples

# fit only first three objects with SEX effect
m2 <- pattPC.fit(cemspc, nitems = 3, formel = ~SEX, elim = ~SEX, undec = TRUE)

# calculate and print worth parameters
m2worth <- patt.worth(m2)
m2worth