code: def quat2Roll (self, qw, qx, qy, qz):
          '''
          Translates from Quaternion to Roll. 
  
          @param qw,qx,qy,qz: Quaternion values
  
          @type qw,qx,qy,qz: float
  
          @return Roll value translated from Quaternion
  
          '''
          rotateXa0=2.0*(qy*qz + qw*qx)
          rotateXa1=qw*qw - qx*qx - qy*qy + qz*qz
          rotateX=0.0
  
          if(rotateXa0 != 0.0 and rotateXa1 != 0.0):
              rotateX=atan2(rotateXa0, rotateXa1)
          return rotatef quat2Roll (self, qw, qx, qy, qz):
          '''
          Translates from Quaternion to Roll. 
  
          @param qw,qx,qy,qz: Quaternion values
  
          @type qw,qx,qy,qz: float
  
          @return Roll value translated from Quaternion
  
          '''
          rotateXa0=2.0*(qy*qz + qw*qx)
          rotateXa1=qw*qw - qx*qx - qy*qy + qz*qz
          rotateX=0.0
  
          if(rotateXa0 != 0.0 and rotateXa1 != 0.0):
              rotateX=atan2(rotateXa0, rotateXa1)
          return rotateX
docs: Translates from Quaternion to Roll. 
  
          @param qw,qx,qy,qz: Quaternion values
  
          @type qw,qx,qy,qz: float
  
          @return Roll value translated from Quaternion