Read a matrix between elements

Hey Guys, I need to read two variables, that have a large amount of samples(30 million values).

I need to select a thousand values from that two variables, correlate them and produce a plot. Then I want to do this again, with new thousand samples, produce a new plot, and so on, till the end of the 30 million values.

I have this code:

So in the first iteration I want Reference_signal_samples(1:1000) and Surveillance_signal_samples(1:1000), do the code

[afmag3,delay3,doppler3], see the plot after the for loop and save it. Next iteration I want Reference_signal_samples(4000:5000) and Surveillance_signal_samples(4000:5000), do the code

[afmag3,delay3,doppler3], see the plot after the for loop and save it. Between iteration I want a step of 3000 samples.

How can i do this in my code, I ve been trying but I cant achieve it

pulse_size = 1000;
%nRef = numel(Reference_signal)/Fs;
%nSurv = numel(Surveillance_signal)/Fs;
nRef = numel(Reference_signal)/pulse_size;
nSurv = numel(Surveillance_signal)/pulse_size;
for k = 1:nRef
    Reference_signal_samples =Reference_signal((k-1)*pulse_size+(1:pulse_size));
    
    for kk =1:nSurv
        
        
        Surveillance_signal_samples=Surveillance_signal((kk-1)*pulse_size+(1:pulse_size));
        [afmag3,delay3,doppler3] = ambgfun(Reference_signal_samples,Surveillance_signal_samples,Fs,[250000 250000]);
        afmag3(afmag3>1 )= 1;
        
    end
    
end

figure;
surf(delay3,doppler3,afmag3,'LineStyle','-.');
shading interp;
axis([-1e-5 1e-5 -2000 2000]); 
grid on; 
view([140,35]); 
colorbar;
ylabel('Doppler (Hz)');
xlabel('Delay(s)');
title('Ambiguity Function Sref');

[dpb]

30E6/1E3 ==> 30,000

What do you propose to do with 30K plots when you're done?

[Miguel Albuquerque]

I need to get that data visualization

[dpb]

I suspect you'll be exhausted long before you can even look at them all -- and the chance of seeing anything unique on one out of 30,000 is remote at best.

[dpb]

OK, I missed the 3000 step interval -- that's a big improvement although 1,000 is still stretching the limits of human endurance and likelihood of really catching anything...

[Miguel Albuquerque]

yep, life ain't easy pal

Answer 1

[dpb]

I'd go at it something like

N=1000;
D=3000;
for i1=1:D:size(x,1)                % starting index each subsection
  i2=i1+N-1;                        % ending index each subsection
  % process here
  result=yourAnalysis(x(i1:i2));    % do your thing with this subset
end

Answer 2

[Sulaymon Eshkabilov]

One of the possible solutions can be using cell array to define the indices, something like this way:

INDEX = {1:1000, 4000:5000, ...}
for ii = 1:10    
for jj = INDEX(ii)
   ... 
end
end