def linear_constraint(u, Lin_lhs, Lin_rhs, tol = 0.05):
    """Check the additional linear constraint on u

    Parameters
    ----------
    u : np.array of shape(None,)
        Beamlet radiation distribution 
    Lin_lhs : np.array of shape(None, u.shape[0])
        Stacked lhs of the constraints
    Lin_rhs : np.array of shape(None,)
        Stacked rhs of the constraints
      
    Returns
    -------
    bool
        Indicator of constraints satisfaction within tol
    """
    return Lin_lhs.dot(u) <= Lin_rhs