GRF value is empty

[visonpon]

Hi @Xinyu-Yi ,thanks for sharing this wonderful work. I tried to get the GRF form this line,
qddot = x[:self.model.qdot_size] GRF = x[self.model.qdot_size:-self.model.qdot_size] tau = x[-self.model.qdot_size:]
my x's shape is 150 and the qdot_size=75, so the GRF is an empty index range. Is there some details I ignored, hope you can help, thank you.

[Xinyu-Yi]

This means that no foot contacts, therefore no grf