How do I plot a 3-d matrix.( error with surf)

I have a 321x60x120 matrix. The matrix has positive and negative float values. I would like to plot it. I tried surf. I get an error saying : "Error using matlab.graphics.chart.primitive.Surface

Value must be a scalar, vector or array of numeric type.". Values are all numeric. What could be wrong?

Is there any other plotting function, that would be recommended. The values are positions and momentums of a 2-d system, that evolve over time. time is the first dimension. The first 60 in the 3rd dimension are positions and the next 60 are momentum of this 2-d system. Ideally, what I want to do, is plot, for each iteration, a 3-d plot for each set of 60 rows and 60 columns of position and then a 3-d plot for each set of 60 rows and 60 positions of momentum, and show the evolution over time.

[Akira Agata]

How about using isosurface ?

[savitha muthanna]

isosurface plots isosurface data from volume data - is it equivalent to surf? And what does the error mean?

[Rafael Hernandez-Walls]

doc slice

Answer 1

[Hitesh]

Hi Savitha,

The error you receive “Error using matlab.graphics.chart.primitive.Surface” suggests that the input that you passed as a parameter does not match specified dimension. You receive this error because you are passing a 3D matrix, whereas surf is allowed to only take 2D matrix as an input.

However, I understand that you are trying to visualize the evolution of position and momentum of a 2D system over time. For that you need to extract 2D slices from your 3D matrix. Since your matrix is 321x60x120, you can think of it as 321-time steps, with each time step containing a 60x120 matrix. This 60x120 matrix can be split into two 60x60 matrices: one for position and one for momentum.

Please refer to below code for reference:

data = rand(321, 60, 120);
for t = 1:size(data, 1)
    % Extract the position and momentum matrices
    positionMatrix = data(t, :, 1:60);
    momentumMatrix = data(t, :, 61:120);
    
    % Reshape to 60x60 matrices
    positionMatrix = reshape(positionMatrix, [60, 60]);
    momentumMatrix = reshape(momentumMatrix, [60, 60]);
    
    % Plot positions
    subplot(1, 2, 1);
    surf(positionMatrix);
    title(['Positions at time step ', num2str(t)]);
    xlabel('X');
    ylabel('Y');
    zlabel('Position');
    shading interp;
    
    % Plot momentums
    subplot(1, 2, 2);
    surf(momentumMatrix);
    title(['Momentums at time step ', num2str(t)]);
    xlabel('X');
    ylabel('Y');
    zlabel('Momentum');
    shading interp;
    
    % Pause for animation effect
    pause(0.1);
end