varcovcubshe {CUB} | R Documentation |
Compute the variance-covariance matrix of parameter estimates of a CUB model with shelter effect.
varcovcubshe(m, pai1, pai2, csi, shelter, n)
m |
Number of ordinal categories |
pai1 |
Parameter of the mixture distribution: mixing coefficient for the shifted Binomial component |
pai2 |
Second parameter of the mixture distribution: mixing coefficient for the discrete Uniform component |
csi |
Feeling parameter |
shelter |
Category corresponding to the shelter choice |
n |
Number of observations |
The function checks if the variance-covariance matrix is positive-definite: if not, it returns a warning message and produces a matrix with NA entries.
Iannario, M. (2012), Modelling shelter choices in ordinal data surveys. Statistical Modelling and Applications, 21, 1–22