AXYZ ( self )

returns the angle, and x,y,z as a vector. as used by glRotate.

XYZR ( self )

Get a VRML-style axis plus rotation form of the rotation. Note that this is in radians, not degrees, and that the angle is the last, not the first item... (x,y,z,radians)

__init__ ( self,  elements=[ 1, 0, 0, 0 ] )

The initializer is a four-element array,

w, x,y,z

all elements should be doubles/floats the default values are those for a unit multiplication quaternion.

__mul__ ( self,  other )

Multiply this quaternion by another quaternion, generating a new quaternion which is the combination of the rotations represented by the two source quaternions.

Other is interpreted as taking place within the coordinate space defined by this quaternion.

Alternately, if "other" is a matrix, return the dot-product of that matrix with our matrix (i.e. rotate the coordinate)

__repr__ ( self )

Return a human-friendly representation of the quaternion

Currently this representation is as an axis plus rotation (in radians)

delta ( self,  other )

Return the angle in radians between this quaternion and another.

Return value is a positive angle in the range 0-pi representing the minimum angle between the two quaternion rotations.

From code by Halldor Fannar on the 3D game development algos list

matrix ( self )

Get a rotation matrix representing this rotation