Function: qdecompose,q Purpose: decompose quaternions into axes and angeles Inputs: q: a 4 element quaternion or an Nx4 element array of quaternions Returns: a 4 element array with a[0] = angle, and a[1:3] = axis, or an Nx4 element array or -1L on failure ;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 As per the euve implementation, if q[0] is outside of the range of acos...[-1,1] the value of the quaternion will be turned into an identity quaternion...in other words clipped, this seems suspect, a better solution may be to wrap the value back into range using modular arithmatic, future modifiers of this routine should consider adding this. 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 $