Missing log_dir in PlottingCallback

[dariomangoni]

In 4_callbacks_hyperparameter_tuning.ipynb I see that PlottingCallback has no log_dir nor self.log_dir variables available, but yet it is called in x, y = ts2xy(load_results(log_dir), 'timesteps')

Did I miss something? It's just a tiny detail...

BTW, thanks for the great job. These tutorial are really helpful and the stable baseline docs are just great!

[araffin]

Hello,
you are right, the callback is actually accessing a global variable defined earlier, it would be cleaner to have it as argument.
and thanks for the kind words =)