#### 2.6.6 Actor Temperature

In all relative probability function formulas mentioned in Relative Probability Function Types, T denotes actor temperature multiplied by some constant. Actor temperature is a concept that follows from the use of exponential forms for the relative probability function resembling formulas related to the Boltzmann distribution. In most relative probability function formulas, actor temperature is a divisor of every spur weight.

The perfect relative probability function is the one that makes it possible for an actor to generate most optimal behavior without the need to tune up actor temperature by hand. That is, for such function, you would always use default temperature equal to 1. If the function is imperfect, its application is not intended one, or when applying the simulated annealing approach for solving a problem, use the following API functions to adjust the temperature of an actor for producing more optimal behavior.

Function: double qsmm_get_actor_ktemperature (qsmm_actor_t actor)

This function returns the temperature (multiplied by some constant) of an actor. If the actor is the large one, the function returns the temperature of a small actor associated with the large actor. A returned value is always finite and positive.

Function: int qsmm_set_actor_ktemperature (qsmm_actor_t actor, double val)

This function sets the temperature (multiplied by some constant) of an actor to val. If the actor is the large one, the function sets the temperature of a small actor associated with the large actor.

On success, the function returns a non-negative value. If val is not a finite or positive number, the function returns negative error code `QSMM_ERR_INVAL`.

The function `qsmm_actor_create` initializes the temperature (multiplied by some constant) of a newly created actor to 1.