code: def sub(self, x, axis):
          
          return self.__array_op(operator.sub, x, axis)
docs: Function to sub 3D View with vector or 2D array (type = numpy.ndarray or 2D Field or 2D View) or 2D View with vector (type = numpy.ndarray)
          :param x: array(1D, 2D) or field (2D) or View(2D)
          :param axis: specifies axis, eg. axis = (1,2) plane lies in yz-plane, axis=0 vector along x axis
          :return: dict with result of operation (same form as view.d)