Plot with multiple x-axes - same scaling

Hello,

I am currently desperate to try to integrate two x-axes with identical y-axes in a plot ...

I have two problems here:

1.) How can I set the x ticks?

The lower axis should go (exactly) from 6.0 to 7.3 in 0.1 steps.

For the upper axis from 8.7 to 10 also in 0.1 steps. These are 14 points for both of them, but somehow that doesn't fit ...

2.) How can I adjust the x label of the lower axis?

Here my try:

yloss5MHz=[1.97203207600000;3.89411108500000;5.76765474000000;12.9537632700000;22.7141478100000;27.1717289300000;35.3378709500000;36.6057307600000;40.2620933300000;39.0743740300000;33.9838793500000;37.6049696900000;32.0796367400000;36.3937195200000]
yloss10MHz=[28.8049171100000;18.7450177100000;24.2295267100000;25.6980862100000;12.9537632700000;12.9537632700000;7.61531124600000;7.62594681400000;5.76765474000000;1.96074554000000;3.88304584800000;5.76765474000000;3.88304584800000;5.82188362800000]

xf5MHz=[6:0.1:7.3]
xf10MHz=[8.7:0.1:10]

f=figure (1)

ax1 = axes();
ax2 = axes('Position', get(ax1, 'Position'), ...  
            'XAxisLocation', 'top', ...                 
            'xlim', [8.7 10], ...                 
            'Color', 'none')                           

linkprop([ax1, ax2], {'ylim', 'Position'});

plot(xf5MHz,yloss5MHz,'Parent',ax1,'Color','k')
hold on 
plot(xf10MHz,yloss10MHz,'Parent',ax2,'Color','k')
grid on
grid minor
legend('1f','2f')
xlabel('Frequency [MHz]') 
ylabel('Amplitude loss [%]')

Thank you so much!

[Mepe]

Many thanks :-)

Answer 1

[Cris LaPierre]

If you haven't yet seen it, I'd recommend this documentation page. I also found this Answers post helpful.

Modifying your code, I came up with this.

yloss5MHz=[1.97203207600000;3.89411108500000;5.76765474000000;12.9537632700000;22.7141478100000;27.1717289300000;35.3378709500000;36.6057307600000;40.2620933300000;39.0743740300000;33.9838793500000;37.6049696900000;32.0796367400000;36.3937195200000];
yloss10MHz=[28.8049171100000;18.7450177100000;24.2295267100000;25.6980862100000;12.9537632700000;12.9537632700000;7.61531124600000;7.62594681400000;5.76765474000000;1.96074554000000;3.88304584800000;5.76765474000000;3.88304584800000;5.82188362800000];

xf5MHz=6:0.1:7.3;
xf10MHz=8.7:0.1:10;

figure
f1 = line(xf5MHz,yloss5MHz,'Color','k');
xlim([6 7.3])
xticks(xf5MHz)
xticklabels(string(xf5MHz))
ax1 = gca; % current axes

ax1_pos = ax1.Position; % position of first axes
ax2 = axes('Position',ax1_pos,...
    'XAxisLocation','top',...
    'YTick',[],...
    'Color','none');

linkprop([ax1, ax2], {'ylim', 'Position'});

f2 = line(xf10MHz,yloss10MHz,'Parent',ax2,'Color','k');
xlim([8.7 10])
xticks(xf10MHz)
xticklabels(string(xf10MHz))

grid on
grid minor
legend([f1,f2],{'1f','2f'})
xlabel(ax1,'Frequency [MHz]') 
ylabel(ax1,'Amplitude loss [%]')