Error in matrix to image

Hi community,

I've created a matrix with structures. This structures are antennas.

%Vertical
ant.elevation = Vertical.Elevation;
ant.VertMagnitude = Vertical.Magnitude; 
%Horizontal
ant.azimuth = Horizontal.Azimuth;
ant.HorizMagnitude = Horizontal.Magnitude;

%Gain and frequency
ant.freq = Optional.frequency;
ant.gain = Optional.gain.value;

I'm getting an error converting the matrix in image. The error is:

Error using image
There is no elevation property on the Image class.

I am converting the matrix to an image using

im = image(gNB,'CDataMapping','scaled');

It seems like the problem is obvious, the structure has an elevation an the class image isn't able to plot it.

How can I turn this matrix in a image? Is the parameters that I am using in image function a part of the problem?

Answer 1

[sanidhyak]

Hi @Oliver Lestrange,

I understand that you are trying to visualize a matrix of structures (representing antennas) using MATLAB’s “image” function, but are encountering an error.

This issue occurs because the “image” function expects a “2D” numeric or RGB array, while you are passing a structure array (“gNB” or “ant”) that contains fields like “elevation”, “magnitude”, etc. The “image” function cannot handle structures directly, hence the error.

To resolve this, you will need to extract a numeric field from your structure (e.g., “VertMagnitude”) and reshape it into a “2D” matrix, if necessary, before visualizing it using “imagesc” or “image” function.

Kindly refer to the following corrected approach:

% Example: Extract Vertical Magnitude and reshape to 2D matrix 
VertMagMatrix = reshape([ant.VertMagnitude], height, width);  % Replace height and width accordingly 

% Display the matrix as an image 
imagesc(VertMagMatrix); 
colorbar; 
title('Vertical Magnitude'); 

If the data is not in a grid format and is instead a “1D” vector, you can use:

bar([ant.VertMagnitude]); 
title('Vertical Magnitude'); 
xlabel('Antenna Index'); 
ylabel('Magnitude'); 

This method enables accurate visualization by first converting the structured data into a “2D” numeric format compatible with image plotting functions.

For further reference on the “image” and “imagesc” functions in MATLAB, kindly refer to:

• https://www.mathworks.com/help/matlab/ref/image.html
• https://www.mathworks.com/help/matlab/ref/imagesc.html

I hope this helps!