extrafrail

Provide estimation and data generation tools for some new multivariate frailty models. This version includes the gamma, inverse Gaussian, weighted Lindley, Birnbaum-Saunders, truncated normal and mixture of inverse Gaussian as the distribution for the frailty terms. For the basal model, it is considered a parametric approach based on the exponential, Weibull and the piecewise exponential distributions as well as a semiparametric approach. For details, see Gallardo and Bourguignon (2022) .