def forward(self, x, u, t=0, terminal=False):
if x.ndimension() == 1:
x = x.unsqueeze(0)
if u.ndimension() == 1:
u = u.unsqueeze(0)
cost = DotMap()
cost.obs = self.obs_cost(x)
if not terminal:
cost.act = self.action_cost(u)
else:
cost.act = 0
l = cost.obs + cost.act
cost.l = l
return cost