Trying to learn how to display an image using app designer

My goal is to display a series of cine images for QA that obviously displays the cine, and adjust the speed, intensity, etc. I am trying to use app designer to do this, which is probably trivial, but I am running into conceptual issues on my part. I have an image JJ created using the following in the Command Window:

 JJ = imagesc(imadjust(dtx(:,:,1))); % where dtx is the cine data in the Workspace and JJ.CData is 128x128 double

Now these variable are in the Workspace and I can share then with other .m programs I have loaded, but when I copy over the mlapp text, edit it and run it, it does not see the current Workspace variables.

So how do I share the Workspace variables? Also I cannot edit the script while in Code View. Why is that the case and how do I modify that?

Text that I am trying to display a single image frame.

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classdef app2test2 < matlab.apps.AppBase

    % Properties that correspond to app components
    properties (Access = public)
        UIFigure  matlab.ui.Figure
        UIAxes    matlab.ui.control.UIAxes
    end

    % App initialization and construction
    methods (Access = public)

        % Create UIFigure and components
        function createComponents(app)

            % Create UIFigure
            app.UIFigure = uifigure;
            app.UIFigure.Position = [100 100 640 480];
            app.UIFigure.Name = 'UI Figure';

            % Create UIAxes
            app.UIAxes = uiaxes(app.UIFigure);
            title(app.UIAxes, 'Title')
            app.UIAxes.XColor = [1 1 1];
            app.UIAxes.XTick = [];
            app.UIAxes.YColor = [1 1 1];
            app.UIAxes.YTick = [];
            app.UIAxes.Position = [72 69 420 310];

        end
    end

    methods (Access = public)

        % Construct app
        function app = app2test2

            % Create and configure components
            createComponents(app)
%              JJ = imagesc(imadjust(dtx(:,:,1)));
             imshow(JJ.CData,'Parent', app.UIAxes);

            % Register the app with App Designer
            registerApp(app, app.UIFigure)

            if nargout == 0
                clear app
            end
        end

        % Code that executes before app deletion
        function delete(app)

            % Delete UIFigure when app is deleted
            delete(app.UIFigure)
        end
    end
end

[Adam]

If I remember correctly, the constructor of App Designer classes now take arguments (they didn't until a very recent version of Matlab) so you can just pass them in there, or put them in a struct or, even better, their own parameter class(es), to pass in if there are a few of them.

[Patrick Ford]

Right now I am attempting to learn how to use App design and want to access the variables in the work space that have been created by other apps to prototype. (Basically I am moving an .m to a have a gui)

I accomplished the effect by saving the image as a .mat file the reopening it.

             X= open('JJ.mat');
             imshow(X.JJ,'Parent', app.UIAxes);
where X is a stuct 1 with field JJ 128 x 128 double
But since I already have the data in ram, this is a lot of extra work and overhead.

Thanks

Answer 1

[Chris Portal]

You can pass workspace variables to your app using a startup function and app input arguments. The approach is described here:

https://www.mathworks.com/help/matlab/creating_guis/app-designer-startup-function.html