The WDTM function returns the magnitude of the difference between the angular acceleration vector of marker i in the reference frame of marker l and the angular acceleration of marker j in the reference frame of marker l.
WDTM(i[,j][,l])
| i | The marker whose acceleration is being measured. |
| j | The marker with respect to which the acceleration is being measured. Set j = 0, while still specifying l, if you want j default to the global coordinate system. |
| l | The reference frame in which the first time derivative of the angular velocity vector is taken. Set l = 0 if you want the time derivatives to be taken in the ground coordinate system (GCS). |
Mathematically, WDTM is calculated as follows:
WDTM(1236,2169)
This function obtains the angular acceleration magnitude of Marker 1236 with respect to Marker 2169, as seen in the global coordinate system and measured in the ground reference frame.