R/dCEWNB.R

In ComRiskModel: Fitting of Complementary Risk Models

#' @export
dCEWNB<-function (x, alpha, beta, theta, s, lambda, log = FALSE)
{
 G=(1-exp(-alpha*x^(beta)))^theta
g=alpha*beta*x^(beta-1)*exp(-alpha*x^beta)*theta*(1-exp(-alpha*x^(beta)))^(theta-1)


  pdf <- x
  pdf[log == FALSE] <-(s*lambda*(g)*(1-lambda*G)^(-s-1))/((1-lambda)^(-s)-1)
  pdf[log == TRUE] <-log(s)+log(lambda)+log(g)+(-s-1)*log(1-lambda*G)-log((1-lambda)^(-s)-1)
  return(pdf)
}