A rotation formula is a formula which transforms a given coordinate system by rotating it through a counterclockwise angle about an axis . Referring to the above figure (Goldstein 1980), the equation
for the "fixed" vector in the transformed coordinate system (i.e., the
above figure corresponds to an alias transformation),
is
(1)
(2)
(3)
(Goldstein 1980; Varshalovich et al. 1988, p. 24). The angle and unit normal may also be expressed as Euler
angles. In terms of the Euler parameters,