def analytical_value_h_phi(distr, par, c):
    """ Analytical value of the Phi entropy for the given distribution.
    
    Parameters
    ----------    
    distr : str
            Name of the distribution.
    par : dictionary
          Parameters of the distribution. If distr = 'uniform': par.a,
          par.b in U[a,b].
    c : float, >=1
        Parameter of the Phi-entropy: phi = lambda x: x**c
      
    Returns
    -------
    h : float
        Analytical value of the Phi entropy.
           
    """
    
    if distr == 'uniform': 
        a, b = par['a'], par['b']
        h = 1 / (b-a)**c
    else:
        raise Exception('Distribution=?')
    
    return h