How to set background image for changing plot without using hold on/off?

Hey Guys!

I have simulated the heat transfer in a Turbine Injector and save the corresponding temperatures for many timesteps in a matrix. I now want to plot this matrix succesively for different timesteps to show the evolution of the heat. However, behind this plot I want to show a picture of the 2D Drawing of the Injector so that you can see where actually the heat is flowing to.

The code shown here works but obviously in this case the drawing of the injector gets replaced by the plotting of the matrix. If I use hold on/off however, the drawing of the injector stays but all the imagesc-plots are overlaid, which I also don't want.

Any ideas?

Thanks so much!

% hold on?
imshow(drawing_2D_injector);

for i = 1:num   %timesteps
    for j = 1:39   
        a = coords{j}; % in coords the coordinates of the flow areas are saved
        A(a) = B(i,j); % in B the temperatures are saved
    end
    colormap(jet);
    imagesc(A,'AlphaData',0.7);
    drawnow
    pause(0.1)
end

Answer 1

[DGM]

I suppose this is one way. I'm sure there are others.

imshow('peppers.png');
hold on % use hold

for i = 1:5 % placeholder value
    A = imresize(randn(20,20),[384 512]); % test overlay
    colormap(jet);
    
    if i ~= 1; delete(himg); end % but delete any prior overlays
    himg = imagesc(A,'AlphaData',0.7);
    
    drawnow
    pause(0.1)
end

[BananaBandana]

Thanks so much my man :) works perfectly