The DY function returns the y-component of the translational displacement vector from marker j to marker i as expressed in the marker k coordinate system. Marker j defaults to the global coordinate system if it is not specified. Similarly, marker k defaults to the global coordinate system if it is not specified.
DY(i[,j][,k])
| i | The marker whose origin is being measured. |
| j | The marker whose origin is the reference point for the displacement calculation. Set j=0 if you want j to default to the global coordinate system while still specifying k. |
| k | The coordinates of the marker that are referenced to calculate coordinates the y-component of the displacement vector is being calculated. Set k = 0 if you want the results to be calculated along the y-axis of the global coordinate system. |
Mathematically, DY is calculated as follows:
where:
is the displacement
of marker i in the global coordinate system.
is the displacement
of marker j in the global coordinate system.
is the unit vector
along the y-axis of marker k.
DY(21,11,32)**2
This function is the square of the y-displacement of Marker 21 with respect to Marker 11 as computed in the coordinate system of Marker 32.