weightedScores: Weighted scores method for regression with dependent data

This package has functions that handle the steps for the weighted scores method in Nikoloulopoulos, Joe and Chaganty (2011, Biostatistics, 12: 653-665) for binary (logistic and probit), Poisson and negative binomial regression, with dependent data. Two versions of negative binomial regression from Cameron and Trivedi (1998) are used. Let NB(tau,xi) be a parametrization with probability mass function f(y;tau,xi)= Gamma(tau+y) xi^y / [ Gamma(tau) y! (1+xi)^(tau+y)], for y=0,1,2,..., tau>0, xi>0, with mean mu=tau*xi = exp(beta^T x) and variance tau*xi*(1+xi), where x is a vector of covariates. For NB1, the parameter gamma is defined so that tau=mu/gamma, xi=gamma; for NB2, the parameter gamma is defined so that tau=1/gamma, xi=mu*gamma. In NB1, the convolution parameter tau is a function of the covariate x and xi is constant; in NB2, the convolution parameter tau is constant and xi is a function of the covariate x.

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