why i am getting blank plot

% PAM Modulation
M_pam = [2, 4, 8]; % Order of PAM modulation
for i = 1:length(M_pam)
    % Generate random binary data
    data = randi([0 M_pam(i)-1], 10, 1);
    
    % PAM modulation
    mod_signal = pammod(data, M_pam(i));
    
    % Plot passband waveform
    figure;
    plot(mod_signal);
    title(['Passband PAM Modulation, M = ', num2str(M_pam(i))]);
    
    % Plot signal space representation (I-Q)
    figure;
    scatterplot(mod_signal, 1, 0, 'b*');
    title(['Signal Space Representation (I-Q) for PAM, M = ', num2str(M_pam(i))]);
end

[Dyuman Joshi]

Check the edit above - I don't see any blank plots.

[pooja]

i was getting 6 plots 3 blank plots , but after removing figure it resolved

[Dyuman Joshi]

How can you have 9 plots when you have only defined 3*2 == 6 plots?

Answer 1

[Mann Baidi]

Hi Pooja,

I understand you are facing issue in plotting graphs in a loop. I would suggest you to remove the "figure" from the "scatter plot" function. You can try this modified code.

M_pam = [2,4,8]; % Order of PAM modulation
for i = 1:length(M_pam)
    % Generate random binary data
    data = randi([0 M_pam(i)-1], 10, 1);
    
    % PAM modulation
    mod_signal = pammod(data, M_pam(i));
    
    % Plot passband waveform
    figure
    plot(mod_signal);
    title(['Passband PAM Modulation, M = ', num2str(M_pam(i))]);
    
    % Plot signal space representation (I-Q)
    
    scatterplot(mod_signal, 1, 0, 'b*');
    title(['Signal Space Representation (I-Q) for PAM, M = ', num2str(M_pam(i))]);
end

Hope this helps!

[Dyuman Joshi]

"I understand you are facing issue in plotting graphs in a loop."

There are no issues. OP has claimed that they are getting blank plots, but that is not the case.

[pooja]

it worked thanks a lot

[Dyuman Joshi]

@pooja, There was no problem with your code to begin with.