How to set YLim for multiple Yaxis on UIaxes

I am plotting a figure using uiaxes in app designer with 2 y axis one on the left and other on the right. And I am trying to set YLim for both left and right. But the code I wrote was wrong. The one I right for the right is overwriting the one on the left. So technically I am only setting YLim for the left one.

yyaxis(app.UIAxes_4,'left');            
plot(app.UIAxes_4,app.actualTime,app.Charge_Current);
app.UIAxes_4.XMinorGrid ="on";
app.UIAxes_4.YMinorGrid ="on";      
app.UIAxes_4.YLabel.String = 'Current [A]';
app.UIAxes_4.YLabel.FontSize = 12;
app.UIAxes_4.YLabel.FontWeight ="bold";
app.UIAxes_4.YLim = [app.Y1min  app.Y1max]; %  This sets the YLim correctly for the left side         

yyaxis(app.UIAxes,'right');            
plot(app.UIAxes,app.actualTime,voltage);            
app.UIAxes.XMinorGrid ="on";
app.UIAxes.YMinorGrid ="on";      
app.UIAxes.YLabel.String = 'Current [A]';
app.UIAxes.YLabel.FontSize = 12;
app.UIAxes.YLabel.FontWeight ="bold";
app.UIAxes_4.YLim = [app.Y2min  app.Y2max]; % This overrides the Ylim set earlier and sets a new YLim for
                                            % left side without setting
                                            % Ylim for the right side. 

What is the way to set Ylim on both left and right. Thank you.

[Sahas]

Hi,

It looks like there might be a small mistake in the code for the right axis but refer to app.UIAxes instead of app.UIAxes_4.

[Govind Sankar Madhavan Pillai Ramachandran Nair]

app.UIAxes_4 is correct because it is the 4th plot. Ther are 3 other plots and the first one is app.UIAxes. But those dont require two y axis, so no problem. This one does, and what is the error.

[Shivam]

Could you attach your app for me to debug the issue? Use the paperclip icon to attach it.

[Govind Sankar Madhavan Pillai Ramachandran Nair]

no I cant attach the app, because there are confidential details in the app. Anyway I just need to know how to set YLim on both Y axis on left and right. How can I do that?

Answer 1

[Jatin]

Hi @Govind Sankar Madhavan Pillai Ramachandran Nair

The line 'yyaxis(app.UIAxes, 'right')' activates the right y-axis for the specified parent, which is app.UIAxes.

Since you haven't used 'yyaxis(app.UIAxes_4, 'right')', your attempt to set the YLim for the right y-axis of app.UIAxes_4 is actually applied to the left y-axis in the last line, as it remains the active side for the app.UIAxes_4 axes.

Refer to the documentation below to learn more about the 'yyaxis':

https://www.mathworks.com/help/matlab/ref/yyaxis.html

Hope it helps!

[Govind Sankar Madhavan Pillai Ramachandran Nair]

Omg, I didnt see that, I am so sorry. That was really stupid. And thank you very much.

[Jatin]

Glad that it was helpful.

Answer 2

[nick]

Hi Govind,

I understand that you want to create a chart with two y-axes each having separate limits.

When the right side of the UI axes is activated using the function 'yyaxis' , it acts upon the object 'app.UIAxes' instead of the 'app.UIAxes_4.YLim' object. This causes the right side of the 'app.UIAxes_4.YLim' object to remain inactive and causes the right to overwrite the one on the left. Here's a sample MATLAB script that implements the two y-axes with different limit:

            time = linspace(0, 10, 100); % Time from 0 to 10 seconds
            current = sin(time); % Dummy current data
            voltage = 10*cos(time); % Dummy voltage data
            
            % Plot on the left y-axis
            yyaxis(app.UIAxes, 'left');
            plot(app.UIAxes, time, current, '-b', 'DisplayName', 'Current');
            app.UIAxes.YLabel.String = 'Current [A]';
            app.UIAxes.YLim = [-1.5, 1.5]; % Example Y limits for the left axis
            app.UIAxes.YLabel.FontSize = 12;
            app.UIAxes.YLabel.FontWeight = 'bold';
            
            % Plot on the right y-axis
            yyaxis(app.UIAxes, 'right');
            plot(app.UIAxes, time, voltage, '-r', 'DisplayName', 'Voltage');
            app.UIAxes.YLabel.String = 'Voltage [V]';
            app.UIAxes.YLim = [-15, 15]; % Example Y limits for the right axis
            app.UIAxes.YLabel.FontSize = 12;
            app.UIAxes.YLabel.FontWeight = 'bold';
            
            % Add grid and title
            app.UIAxes.XMinorGrid = 'on';
            app.UIAxes.YMinorGrid = 'on';
            title(app.UIAxes, 'Current and Voltage vs. Time');
            xlabel(app.UIAxes, 'Time [s]');
            legend(app.UIAxes, 'show');
            

You can refer to the following documentation to learn more about the function 'yyaxis':

https://www.mathworks.com/help/matlab/ref/yyaxis.html

Hope this helps.