question about computeTwist

[oldton]

hi aynga i am reading the code of FROST now, there is a question about the function computeTwist of RobotJoint. in this function,you set the twist of RobotJoint as: obj.Twist = transpose(adj*transpose(xi));

   and the comment about the function is :
 %computes the twist from the base frame

   i think the twist should be twist from parent frame ,not from base frame.
  am i misunderstand  something?