def gravity(self,q): return se3.rnea(self.model,self.data,q,self.v0,self.v0)
def biais(self,q,v): return se3.rnea(self.model,self.data,q,v,self.v0)
def gravity(self, q): return se3.rnea(self.model, self.data, q, self.v0, self.v0)