ihgcov: Main function for IHG models with covariates
Description
Estimate and validate an IHG model for given ordinal responses, with covariates to
explain the preference parameter.
Usage
ihgcov(m, ordinal, U, makeplot, summary)
Arguments
m
Number of ordinal categories
ordinal
Vector of ordinal responses
U
Matrix of selected covariates for the preference parameter
makeplot
Logical: if TRUE and if only one dichotomous covariate is included in the model, with levels (0,1),
the function returns a graphical plot comparing the distributions of the responses conditioned to the value of the
covariate
summary
Logical: if TRUE, summary results of the fitting procedure are displayed on screen
Value
An object of the class "IHG"An object of the class "IHG"
Details
The optimization procedure is run via "optim", option method="Brent" for constrained optimization
(lower bound = 0, upper bound=1).