MATLAB: Superimposing two imagesc graphs over each other.

Question

I have a matrix P which varies with time t,

P(:, :, t) ;

a variable Pmax,

Pmax = max(max(P(;,:,t)));

which I visualise through imagesc, step by step to create an animation:

figure

for i = 1:10:1000

imagesc(P(:, :, i), [0, Pmax]);

axis square

colorbar

end

I have another variable B, which I would like to visualise superimposed over the first imagesc plot, in a different colorbar/colour grading as P.

How could this be achieved? I was thinking of using a surf plot viewed from above instead (the two plots would be 2D, and the view set directly above to seem as a 2D plot). However to achieve this through the imagesc command would be much better.

Please share any ideas below, thank you!

Answer 1

It is difficult to give exact solution without the exact data. But, below is an example of how you can superimpose 2 data using imagesc with different transparency & colormap.

%plot first data 
ax1 = axes; 
im = imagesc(ax1,imread('cameraman_512.png')); 
im.AlphaData = 0.5; % change this value to change the background image transparency 
axis square; 
hold all; 
%plot second data 
ax2 = axes; 
im1 = imagesc(ax2,imread('fighter.png')); 
im1.AlphaData = 0.5; % change this value to change the foreground image transparency 
axis square; 
%link axes 
linkaxes([ax1,ax2]) 
%%Hide the top axes 
ax2.Visible = 'off'; 
ax2.XTick = []; 
ax2.YTick = []; 
%add differenct colormap to different data if you wish 
colormap(ax1,'summer') 
colormap(ax2,'winter') 
%set the axes and colorbar position 
set([ax1,ax2],'Position',[.17 .11 .685 .815]); 
cb1 = colorbar(ax1,'Position',[.05 .11 .0675 .815]); 
cb2 = colorbar(ax2,'Position',[.88 .11 .0675 .815]);