PHI
The PHI function calculates the third angle (in radians) of a body-fixed-3-1-3 Euler rotation sequence between markers i and j. Marker j defaults to the global coordinate system if it is not specified. See Figure 7 for a schematic description of the body-fixed-3-1-3 Euler rotation sequence.
Format
PHI(i[,j])
Arguments
i | The marker whose rotations are being sought. |
j | The marker with respect to which the rotations are being measured. |
Examples
REQUEST/1, F2=PHI(222,434)
This REQUEST statement output the phi angle between Markers 222 and 434 in its second column.
See other Displacement available.
Figure 7 Body-fixed-3-1-3 Euler Angles
 | The body-fixed-3-1-3 sequence is started by rotating counterclockwise the initial system of axes, xyz, by an angle  about the z-axis. The resultant axes are labeled  . (Notice that z coincides with  . )In the second stage the intermediate axes,  , are rotated counterclockwise about the  -axis by an angle  . The new resultant planes are labelled  '  '  '. The  '- axis is at the intersection of the xy and  '  ' planes and is known as the line of nodes. (Notice that  coincides with  '.)In the final rotation, the  '-  '- z '- axes are rotated counterclockwise by an angle  about the  -axis to produce the x' y' z' axes, which is the desired final direction. (Notice that  coincides with  '.) |