function b = subsref(a, s)
% SUBSREF
switch s.type
    case '()'
        ind = s.subs{:};
        b = zeros(1, length(ind));
        for k = 1:length(ind)
            b(k) = funcmethods(2, a.index, ind(k));
        end
    otherwise
        error('Specify value for x as p(x)')
end