Surf 3D Matrix size issue

Hello everyone,

currently i try to understand some code i got from my supervisor in college. My task is to create a 3D plot. I've got vector V.x with dimension 1x41 and a vector V.y with dimension 1x41 as well. Besides that i got a 3D Matrix E with the dimension 41x41x301.

I tried to use surf(V.x,V.y,E).

I get an error because of the dimensions must agree.

Where is the Problem? Is it because of the "x301", because E is a 3D Matrix?

If so, how can i fix it?

Sincerely

Lucas

Answer 1

[Ameer Hamza]

Yes, It is because of 3D array. Are you trying to create 301 surfaces? You can plot a single surface like this

surf(V.x, V.y, E(:,:,1))

To plot all 301 surfaces on single axes, use for loop

n = size(E,3);
figure;
ax = axes();
hold(ax)
for i=1:n
    surf(V.x, V.y, E(:,:,i));
end

[Lucas Junghans]

Thanks for the answer.

Well do be honest im still not quite sure how this all should work.

My supervisor told me that i should try to get a plot.

I guess firstly you probably need some more Information. So I've got the vector V.x which are just some x - values the same with V.y, but E is the Electric Field and therefor kind of like the intensity of light, since I ~ |E|^2 .

What i should try is to get a plot, where x = x values, y = y values , z = the Intensity (|E|^2) and the color should be the phase of E. But would it not be a 4D plot? Im still kind of new to Matlab, by the way.

And is it possible to still use surf? i thought i could use surf(X,Y,Z,C) with C = color = the Phase.

hopefully my problem is understandable :)

Best greetings

Lucas

Edit: Oh and i forgot to mention, that my E has complex values.

[Lucas Junghans]

Ok. I guess i just solved my problem thanks to your answer :)

So thanks again.

n = size(E,3);
    ax = axes();
    hold(ax)
    for i=1:n
        surf(V.x, V.y, abs(squeeze(E(:,:,i).^2)),angle(squeeze(E(:,:,i).^2)));
    end

[Ameer Hamza]

I am glad to be of help.

Yes. You can use surf to display a 4th-dimensional value on a surface.