Wrong initialization of transformer mixer hyperparameters

[wzz618]

In your papar, transformer mixer has only 3 hyperparameters, but when initializing you initialize the hyperparameters by the number of n_agents:
Your codes:

# src/modules/mixers/n_transf_mixer.py (code: 52-53)
def init_hidden(self):
    return th.zeros(1, self.n_agents, self.args.emb).to(self.args.device)

Need to be

def init_hidden(self):
    return th.zeros(1, 3, self.args.emb).to(self.args.device)

And same in

# src/learners/nq_transf_learner.py (code: 112)
# src/learners/nq_transf_learner.py (code: 137)