Multiple y axes with multiple plots on single x axis

Dear all,

I tried to plot three y-axis where each y-axis contains two lines. I used the approach described in this post: https://nl.mathworks.com/matlabcentral/answers/459385-multiple-y-axes-on-single-x-axis#answer_372987

However, the x-ticks and y-thicks overlap each other. How can I solve this?

close all

figure
grid on
ax1 = axes;
yyaxis left
plot(theta_p{5},dW_closing_winches{5},'linewidth',1.5)
hold on
plot(theta_p{6},dW_closing_winches{6},'linewidth',1.5)
pause(0.1)
xlabel('\theta [%]','FontWeight','bold')
ylabel('Work [J]','FontWeight','bold')
ax1.XTickMode = 'manual'; 
ax1.YTickMode = 'manual'; 
ax1.YLim = [min(ax1.YTick), max(ax1.YTick)];  % see [4]
ax1.XLimMode = 'manual'; 
grid(ax1,'on')
ytick = ax1.YTick;  
yyaxis right
plot(theta_p{5},dW_HDP{5},'linewidth',1.5)
hold on
plot(theta_p{6},dW_HDP{6},'linewidth',1.5)
ylabel('Work [J]','FontWeight','bold') 
ax2 = axes('position', ax1.Position);
plot(ax2,theta_p{5},(dW_closing_winches{5}+dW_HDP{5}),'k')
hold on
plot(ax2,theta_p{6},(dW_closing_winches{6}+dW_HDP{6}),'--k')
pause(0.1)
ax2.Color = 'none'; 
grid(ax2, 'on')
% Horizontally scale the y axis to alight the grid (again, be careful!)
ax2.XLim = ax1.XLim; 
ax2.XTick = ax1.XTick; 
ax2.YLimMode = 'manual'; 
dW_HDP{5} = ax2.YLim; 
ax2.YTick = linspace(dW_HDP{5}(1), dW_HDP{5}(2), length(ytick));      % see [2]
% horzontally offset y tick labels
ax2.YTickLabel = strcat(ax2.YTickLabel, {'       '}); 

Answer 1

[Adam Danz]

Take a look at these 3 lines below.

figure
grid on   
ax1 = axes;

Line 1 creates a new figure.

grid on not only turns on the grid but also creates axes.

ax1 = axes creates a second set of axes directly on top of the first axes.

To fix this, move grid on to some point after the axes are created and get into the habit of always using parent handles to specify the parent of a graphics object.

fig = figure();         % GET HANDLE
%  grid on              % REMOVE
ax1 = axes(fig);        % SPECIFY PARENT
yyaxis(ax1,'left')      % SPECIFY PARENT
plot(ax1,theta_p{5},dW_closing_winches{5},'linewidth',1.5)  % SPECIFY PARENT
hold(ax1,'on')          % SPECIFY PARENT
grid(ax1,'on')          % ADD THIS

you can do the rest :)

[Tessa Kol]

Thank you!

[Tessa Kol]

Is it also possible to use in combination with a for loop? So I can plot multiple data sets in one figure. No I have to manually add another plot with the code below.

close all

figure
ax1 = axes;
yyaxis left
p1=plot(theta_p{5},dW_closing_winches{5},'linewidth',1.5);
hold on
p2=plot(theta_p{6},dW_closing_winches{6},'linewidth',1.5);
xlabel('\theta [%]','FontWeight','bold')
ylabel('Work [J]','FontWeight','bold')
pause(0.1)
ax1.XTickMode = 'manual'; 
ax1.YTickMode = 'manual'; 
ax1.YLim = [min(ax1.YTick), max(ax1.YTick)];  % see [4]
ax1.XLimMode = 'manual'; 
grid(ax1,'on')
ytick = ax1.YTick;  

yyaxis right
p3=plot(theta_p{5},dW_HDP{5},'linewidth',1.5);
hold on
p4=plot(theta_p{6},dW_HDP{6},'linewidth',1.5);
ylabel('Work [J]','FontWeight','bold') 

ax2 = axes('position', ax1.Position);
p5=plot(ax2,theta_p{5},(dW_closing_winches{5}+dW_HDP{5}),'k');
hold on
p6=plot(ax2,theta_p{6},(dW_closing_winches{6}+dW_HDP{6}),'--k');
ylabel('Work [J]','FontWeight','bold')
pause(0.1)
ax2.Color = 'none'; 
grid(ax2, 'on')
% Horizontally scale the y axis to alight the grid
ax2.XLim = ax1.XLim; 
ax2.XTick = ax1.XTick; 
ax2.YLimMode = 'manual'; 
ax2.YTick = linspace(ax2.YLim(1), ax2.YLim(2), length(ytick));      % see [2]
% horzontally offset y tick labels
ax2.YTickLabel = strcat(ax2.YTickLabel, {'              '}); 
set(gcf, 'Position',  [500 200 900 760])
title(['Work flat surface - nemaX grab - ',Simulation_names{5},' & ',Simulation_names{6}])
legend([p1;p2;p3;p4;p5;p6],{'Work_{closing winches T50 / 4 s}','Work_{closing winches T50 / 5 s}','Work_{HDP T50 / 4 s}','Work_{HDP T50 / 5 s}','Work_{total T50 / 4 s}','Work_{total T50 / 5 s}'},'location','northwest')
annotation('textbox',[0.12 0.06 0 0],'String','Open','FontWeight','bold');
annotation('textbox',[0.85 0.06 0 0],'String','Closed','FontWeight','bold');

[Adam Danz]

I only looked at your code briefly but it looks like you could do that in a for loop or as you have written it.

[Tessa Kol]

I tried a different data set with the same code. However, the x-axis of ax2 is shifted with respect ot ax1. What could be the problem?

[Adam Danz]

It looks like you're not setting the xlim for both axes.

First try using linkaxes (see documentation).

Alternatively, set the xlim of both axes. linkaxes is better because if one axis limit changes, the other will be updated.

[Tessa Kol]

With the following lines of code, which are already specified in the code, I assume that the xlim of both axis are set to the same values, right?

% Horizontally scale the y axis to alight the grid
ax2.XLim = ax1.XLim; 
ax2.XTick = ax1.XTick; 

[Adam Danz]

That looks OK. Upon closer look, the axis positions appear to be the problem.

Link the axis positions using linkprop.

[Tessa Kol]

I figured out what the problem was. I added the following line of code:

set(gcf, 'Position',  [500 200 900 760])

But this was only set for the last two plots (p5 and p6). Therefore, those plots didn't align with the previous ones. I added the above line of code to the other plots and it works perfectly.

I want to thank you for your help and I learned a lot from the advised functions.

[Adam Danz]

That's why linkprops is useful. Once the axis positions are linked, changes to one axis will copy to the second axes. Glad I could help.