The UVZ measure returns the unit vector in the direction of the z axis of marker i, resolved in the coordinate system of marker k.
Format
UVZ(i[,k])
Arguments
i | The marker whose z-axis unit vector is being measured. |
k | The marker in whose coordinate system the unit vector is being expressed. If k is not specified, k defaults to the global coordinate system. |
Extended Definition
Mathematically, UVZ is calculated as:
where:
■
is the unit vector along the z-axis of marker i.
■
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 z-axis of marker k.
Examples
VARIABLE/1, FUN=DXYZ(i,j)*UVZ(k)
VARIABLE/2, FUN=DZ(i,j,k)
Variables 1 and 2 are synonymous. They both produce the translational displacement between markers i and j along the direction of the z-axis of marker k.
See other
Vector measures available.