code: def normalize(self):
          '''re-normalise a rotation matrix'''
          error = self.a * self.b
          t0 = self.a - (self.b * (0.5 * error))
          t1 = self.b - (self.a * (0.5 * error))
          t2 = t0 % t1
          self.a = t0 * (1.0 / t0.length())
          self.b = t1 * (1.0 / t1.length())
          self.c = t2 * (1.0 / t2.length()f normalize(self):
          '''re-normalise a rotation matrix'''
          error = self.a * self.b
          t0 = self.a - (self.b * (0.5 * error))
          t1 = self.b - (self.a * (0.5 * error))
          t2 = t0 % t1
          self.a = t0 * (1.0 / t0.length())
          self.b = t1 * (1.0 / t1.length())
          self.c = t2 * (1.0 / t2.length())
docs: re-normalise a rotation matrix