when I want to get the coordinate of the joint in the parent frame, Is there a bug in the function "getJointInfo"?

[huxiaoyi0625]

I want to get the coordinate of the joints in the parent frame, but I found that the function "getJointInfo" seemed that couldn't give me the correct coordinate. To verify my guess, I plus the coordinate of the base and the coordinate of the joint'0', which is the children frame of the base frame. Then, I made a marker in the position of the summed coordinate. At first, it was in the correct position. However, when I moved the body of the robot, the marker was in the wrong place.