Creating subplots in a for cycle with App Designer

Hi all,

I’m trying to create subplots within a Panel with a for cycle in App Designer.

I was able to implement my first 3 subplots in a single panel in the following way:

app.subplot1(3,1,1,'Parent',app.Plotpanel);

plot(app.subplot1,t,a(:,1),’g’]);

hold(app.subplot1);

app.subplot2(3,1,2,'Parent',app.Plotpanel);

plot(app.subplot2,t,a(:,2),’b’]);

hold(app.subplot2);

app.subplot3(3,1,3,'Parent',app.Plotpanel);

plot(app.subplot3,t,a(:,3),’r’]);

hold(app.subplot3);

I have defined my subplots at the beginning of the app in the following way:

properties (Access = public)

subplot1 matlab.ui.control.UIAxes % Description

subplot2 matlab.ui.control.UIAxes % Description

subplot3 matlab.ui.control.UIAxes % Description

Supposing that my matrix a to plot is actually is bigger than 3 columns and I want to plot, at any cycle, columns 1,2,3 and then 4,5,6 and then 7,8,9 etc etc..

How can I implement that in App Designer? If I write this:

figure(n3) %n3 is the index that moves the columns of a in a for cycle

app.subplot1(3,1,1,'Parent',app.Plotpanel);

plot(app.subplot1,t,a(:,1),’g’]);

hold(app.subplot1);

I get this message: Unable to use a value of type matlab.ui.container.Panel as an index.

I would like that every set of 3 columns of the data are plotted as subplots in the same panel, maybe adding a sort of scrolling tab, is this possibile?

I hold Matlab R2022a. Thanks to everyone who will be able to help me.

Answer 1

[Kevin Holly]

I created an app that generates tabs and subplots based on the dimensions of matrix a. Please see the app attached. I did not use subplots but used axes() instead.

[IS]

Many thanks Kevin, this is very useful to me to understand the general App Designer workflow!

[Iacopo]

Hi Kevin,

Do you also know how I can refresh the tabs content after changing the number of rows/columns? Because for example if I plot less number of columns after the first plot, the previous plots will still be displayed. Thank you

[Kevin Holly]

You can add the lines:

            delete(app.TabGroup.Children(2:end))
            delete(app.TabGroup.Children(1).Children)

within the push button callback as shown below

function PlotMatrixButtonPushed(app, event)
            a = rand(app.RowsEditField.Value,app.ColumnsEditField.Value);
            
            delete(app.TabGroup.Children(2:end))
            delete(app.TabGroup.Children(1).Children)

            for i = 4:3:size(a,2)
                if ceil(i/3) > size(app.Panel.Children.Children)
                    uitab(app.TabGroup,'Title',['Set' num2str(ceil(i/3))])
                end
            end

            for i = 1:3:size(a,2)
                ax1 = axes(app.Panel.Children.Children(ceil(i/3)),"Position",[0.1300 0.7093 0.7750 0.2157]);
                plot(ax1,a(:,i))
                if i+1 <=size(a,2)
                    ax2 = axes(app.Panel.Children.Children(ceil(i/3)),"Position",[0.1300 0.4096 0.7750 0.2157]);
                    plot(ax2,a(:,i+1))
                end
                if i+2 <=size(a,2)
                    ax3 =axes(app.Panel.Children.Children(ceil(i/3)),"Position",[0.1300 0.1100 0.7750 0.2157]);
                    plot(ax3,a(:,i+2))
                end
            end
        end