Function: qnormalize Purpose: normalize a quaternion or an array of quaternions Inputs: q: a 4 element array, or an Nx4 element array, representing quaternion(s) Returns: q/(sqrt(norm(q))) or -1L on fail Notes: Implementation largely copied from the euve c library for quaternions Represention has q[0] = scalar component q[1] = vector x q[2] = vector y q[3] = vector z The vector component of the quaternion can also be thought of as an eigenvalue of the rotation the quaterion performs Written by: Patrick Cruce(pcruce@igpp.ucla.edu) $LastChangedBy: pcruce $ $LastChangedDate: 2007-11-11 17:12:08 -0800 (Sun, 11 Nov 2007) $ $LastChangedRevision: 2027 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/trunk/cotrans/cotrans.pro $