how do I extract the graph so that the x-axis becomes a frame

1.present situation

Fig.0

Fig.1

Figure 0 is a numeric representation of the bin file. Based on the number of cells, we extracted the graph of Fig.1 by frame (code is below).

For example, suppose it's a 32 frame, we've written code to have 32 pictures like this. in other words, a graph with velocity information is drawn for each frame.

2. what I want

Fig.2

Like the graph in Figure 2., I want to show all the velocities of each frame in a single graph.

3. my code

What code should I add to represent the x-axis as a frame (time) as shown in Figure 2?

%% ADC data per frame
i = 0; % For recording the number of times
numframe = 32;
for n=1:numframe
    A = adcData(1, (32768*(n-1)+1):numADCSamples*numChirps/numframe*n);
    A = reshape(A, [numADCSamples, numChirps/numframe]); % column-numADCSample row-numChirps
    % return receiver data % adcData FFT
    radar_data_1dFFT = fftshift(fft(A,[], 2));%.*window_1D
    fftSize1D = size(radar_data_1dFFT);
    radar_data_2dFFT = fft(radar_data_1dFFT,[], 1);%.*window_2D
    fft_out = radar_data_2dFFT;
    %fft_out = fftshift(fft_out);
    fft_out = 20*log10(abs(fft_out));
    %% 횟수 기록
    i = i+1;
    %% Obtain range-velocity map after performing 2d fft
    % range
    c = 3e8; % speed of light
    s = 29.9817e15; % slope of chirp signal
    Fs = 7675e6; 
    fb = Fs/(numADCSamples-1)*(0:(numADCSamples-1)); % beat frequency
    range = (c*fb)/(2*s);
    
    % velocity
    lamda = 5e-3; % Tx signal length
    PRT = 310.8e-6; PRF = 1/PRT; % PRF = Pulse Repitition Frequency, PRT = ..Time
    velocity = PRF/(numChirps/numframe-1)*(0:(numChirps/numframe-1))*lamda/4*pi;  
    
    % plot
    figure;  % two dimension
    imagesc(-velocity, -range ,abs(fft_out));
    xlabel('velocity(m/s)');ylabel('range(m)');
    % save image
    myfilename = sprintf('Going%d.png', i);
    saveas(gcf, myfilename)
end

Answer 1

[Varun]

Hello!

As per my understanding, you want to put together all the frames generated in the loop side-by-side in the same figure. Since, you are saving all the plots generated as image files (.png), you can use the ‘imtile’ function to arrange the plots frame by frame. You can customise the grid size and other parameters to get the figure you need. You may find the documentation for ‘imtile’ at: https://www.mathworks.com/help/matlab/ref/imtile.html#mw_dcf93777-52b2-49db-a80e-c61ad515dd7b

Hope this helps!