How to use UIAxes to display image in app viewer

I am trying to reproduce a figure in my .m script in App Designer .mlapp script. I want to display a gray scale image and overlay on that image a yellow box, and also overlay a contour of the image all in one figure. I can do this in my .m script with imoshow(insertshape(img)); hold, contour(img) as shown below:

figure(6)
imshow(insertShape(ImgOut(:,:,round(Planes/2)),'FilledRectangle', mbox, 'Color', 'yellow', 'Opacity', 0.2),[])
title(['Site',num2str(s),' measurement ROI box placement'])
hold all
contour(ImgOut(:,:,round(Planes/2)),[TH,TH],'LineColor','white')

I want to imbed this figure in my App Designer .mlapp script using UIAxes command. I can display the image with the yellow box but I can't overlay the contour. This is what I've tried and it only displays the image with box, no contour:

imshow(insertShape(ImgOut(:,:,round(Planes/2)),'FilledRectangle', mbox, 'Color', 'yellow', 'Opacity', 0.2),[],'Parent',app.UIAxes)            
hold all
contour(ImgOut(:,:,round(Planes/2)),[TH,TH],'LineColor','white')

Answer 1

[Cris LaPierre]

I suspect you need to specify the parent axes for the contour plot

contour(app.UIAxes,ImgOut(:,:,round(Planes/2)),[TH,TH],'LineColor','white')

[Scott Chegwidden]

Thanks but this just replaces my ImgOut with the contour. What I want to do is overlay the contour on top of the image so I can see both of them in the same figure.

[Cris LaPierre]

I'm not testing this, but you do say the code at the top worked in a script, right? Try adding this hold command immediately before adding the contour plot.

hold(app.UIAxes,'on')

[Scott Chegwidden]

This works! Guess I just needed the right hold syntax. Thanks!!