Translational Displacement Vector (DXYZ)
The DXYZ measure returns the translational displacement vector from marker j to marker i as expressed in the coordinate system of marker k.
Format
DXYZ(i[,j][,k])
Arguments
To Marker (i) | The marker whose origin is being measured. |
From Marker (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. |
Reference Frame (k) | The marker in whose coordinate system the displacement vector is being expressed. If not specified, k defaults to the global coordinate system. |
Extended Definition
where:
■
is the displacement of marker i with respect to the global origin.
is the displacement of marker i with respect to the global origin.■
is the displacement of marker j with respect to the global origin.
is the displacement of marker j with respect to the global origin.■DX is the Distance Along X (DX) measure.
■DY is the Distance Along Y (DY) measure.
■DZ is the Distance Along Z (DZ) measure.
■
is the unit vector along the x-axis of marker k.
is the unit vector along the x-axis of marker k.■
is the unit vector along the y-axis of marker k.
is the unit vector along the y-axis of marker k.■
is the unit vector along the z-axis of marker k.
is the unit vector along the z-axis of marker k.Examples
The following statement:
VARIABLE/1, FUNCTION=MAG(DXYZ(21,11,32))
is equivalent to:
VARIABLE/1, FUNCTION=DM(21,11)
and because a magnitude is taken, the use of the coordinate system of marker 32 as an alternative to the ground coordinate system is redundant (and wasteful).