The func_tensor_opt(), dfunc_tensor_opt(), and d2func_tensor_opt() methods have been merged with the
func_population(), dfunc_population(), and d2func_population() methods into the new func_standard(),
dfunc_standard(), and d2func_standard() methods. This halves the amount of code required to be
maintained and debugged. For the merger, the new probs_fixed class instance variable has been
created to determine when the probabilities need to be unpacked from the parameter vector.
