How can i use linkaxes with multiple imshow in appdesigner?

I wanna show all three layers of an RGB (or other color spaces) image and link them together with the original image to perform treshold operations with some spinner or slider. This is what i've tried so far:

properties (Access = private)

ax0 matlab.graphics.axis.Axes

ax1 matlab.graphics.axis.Axes

ax2 matlab.graphics.axis.Axes

ax3 matlab.graphics.axis.Axes

end

%reading image

[file,path]=uigetfile('*','Load');

filename=sprintf('%s%s',path,file);

filename = convertCharsToStrings(filename);

I = imread(filename);

%layers with max and min

I1=I(:,:,1); I1_down=min(min(I1)); I1_up=max(max(I1));

I2=I(:,:,2); I2_down=min(min(I2)); I2_up=max(max(I2));

I3=I(:,:,3); I3_down=min(min(I3)); I3_up=max(max(I3));

imshow(I,'Parent',app.UIAxes_tot); %original img

imshow(I1,[I1_down I1_up],'Parent',app.UIAxes_1); %1st layer

imshow(I2,[I2_down I2_up],'Parent',app.UIAxes_2); %2nd layer

imshow(I3,[I3_down I3_up],'Parent',app.UIAxes_3); %3rd layer

app.ax0 = axes(app.UIAxes_tot);

app.ax1 = axes(app.UIAxes_1);

app.ax2 = axes(app.UIAxes_2);

app.ax3 = axes(app.UIAxes_3);

linkaxes([app.ax0,app.ax1,app.ax2,app.ax3]);

this is the error:

Error using axes

Too many output arguments.

(line 56)

app.ax0 = axes(app.UIAxes_tot);

what is the problem?

Answer 1

[Benjamin Kraus]

linkaxes only started working with UIAxes in MATLAB R2020b.

• If you are using an older release and you cannot upgrade, I recommend switching from using UIAxes to regular axes. Regular axes have worked in App Designer since MATLAB R2018b, but you have to create them programmatically using the axes command (rather than dragging and dropping them when designing your app).
• If you are using MATLAB R2020b, this code is unnecessary and is what is causing the problem:

app.ax0 = axes(app.UIAxes_tot);
app.ax1 = axes(app.UIAxes_1);
app.ax2 = axes(app.UIAxes_2);
app.ax3 = axes(app.UIAxes_3);
linkaxes([app.ax0,app.ax1,app.ax2,app.ax3]);

All you should need is this:

linkaxes([app.UIAxes_tot,app.UIAxes_1,app.UIAxes_2,app.UIAxes3]);