code: def quaternion_conjugate(quaternion):
      
      q = numpy.array(quaternion, dtype=numpy.float64, copy=True)
      numpy.negative(q[1:], q[1:])
      return q
docs: Return conjugate of quaternion.
  
      >>> q0 = random_quaternion()
      >>> q1 = quaternion_conjugate(q0)
      >>> q1[0] == q0[0] and all(q1[1:] == -q0[1:])
      True