optim within 
  rrvglm are set using this function.rrvglm.optim.control(Fnscale = 1, Maxit = 100,
                     Switch.optimizer = 3, Abstol = -Inf,
                     Reltol = sqrt(.Machine$double.eps), ...)optim as fnscale.optim as maxit.optim is switched to the quasi-Newton "BFGS" method.
  Assigning Switch.optimizer a negative number
  means always BFGS, while assigning Switch.optimizer a value 
 optim as abstol.optim as reltol.optim for more details.rrvglm.control,
  optim.