Matlab绘制第二个x轴位置

Question

我尝试添加第二个x轴，它可以只是第一个x的副本，相同的数据。 但是当我添加轴时它不会改变y位置，如同指定的那样，它也会改变x并且轴本身被切割，不可见

f = 10;
N=[3,5,8,13];

eff_t(1) = 12.4758 - j *6.5914;
eff_f(1) = 12.4615;

n_t(1) = 0.0298;
n_est(1) = 0.0321;

eff_f(2) = 12.3662 - j *7.473;
eff_t(2) = 12.3532 - j *6.5202;

n_t(2) = 0.0496;
n_est(2) = 0.0475;

eff_f(3) = 12.0535 - j *6.327;
eff_t(3) = 12.1708 - j *6.4143;

n_t(3) = 0.0794;
n_est(3) = 0.0987;

eff_f(4) = 12.0328 - j *6.4102;
eff_t(4) = 11.8707 - j *6.2402;

n_t(4) = 0.12;
n_est(4) = 0.10;

figure(1)
yyaxis left
plot(N, eff_f,'b-o', N, eff_t, 'r-o','Linewidth',2);
ylabel('Realteil der rel. Permittivität \epsilonS und \epsilonMG');
yyaxis right
plot(N, n_est, 'k--o',N, n_t,'g--o','Linewidth',2);
ylabel('Porosität nS und nMG');

legend('\epsilonS','\epsilonMG','nS','nMG');

grid on
%grid minor
set(gca,'FontSize', 20);
set(gca,'Linewidth',1.8);

 xlabel('N Anzahl der Poren');

 title('Permittivität und Porosität für f = 10 GHz');

 a1Pos = get(gca,'Position');

%// Place axis 2 below the 1st.
ax2 = axes('Position',[a1Pos(1) (a1Pos(2)-0.3) a1Pos(3) a1Pos(4)],'Color','none','YTick',[],'YTickLabel',[]);