# inibestcubecov: Preliminary parameter estimates for CUBE models with... In CUB: A Class of Mixture Models for Ordinal Data

## Description

Compute preliminary parameter estimates for a CUBE model with covariates for all the three parameters. These estimates are set as initial values to start the E-M algorithm within maximum likelihood estimation.

## Usage

 `1` ```inibestcubecov(m,ordinal,Y,W,Z) ```

## Arguments

 `m` Number of ordinal categories `ordinal` Vector of ordinal responses `Y` Matrix of selected covariates to explain the uncertainty parameter `W` Matrix of selected covariates to explain the feeling parameter `Z` Matrix of selected covariates to explain the overdispersion parameter

## Value

A vector `(inibet, inigama, inialpha)` of preliminary estimates of parameter vectors for π = π(\bold{β}), ξ=ξ(\bold{γ}), φ=φ(\bold{α}), respectively, of a CUBE model with covariates for all the three parameters. In details, `inibet`, `inigama` and `inialpha` have length equal to NCOL(Y)+1, NCOL(W)+1 and NCOL(Z)+1, respectively, to account for an intercept term for each component.

`inibestcube`, `inibestcubecsi`, `inibestgama`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17``` ```data(relgoods) m<-10 naord<-which(is.na(relgoods\$Tv)) nacovpai<-which(is.na(relgoods\$Gender)) nacovcsi<-which(is.na(relgoods\$year.12)) nacovphi<-which(is.na(relgoods\$EducationDegree)) na<-union(union(naord,nacovpai),union(nacovcsi,nacovphi)) ordinal<-relgoods\$Tv[-na] Y<-relgoods\$Gender[-na] W<-relgoods\$year.12[-na] Z<-relgoods\$EducationDegree[-na] ini<-inibestcubecov(m,ordinal,Y,W,Z) p<-NCOL(Y) q<-NCOL(W) inibet<-ini[1:(p+1)] # Preliminary estimates for uncertainty inigama<-ini[(p+2):(p+q+2)] # Preliminary estimates for feeling inialpha<-ini[(p+q+3):length(ini)] # Preliminary estimates for overdispersion ```