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I am not able to get this error removed. Can someone please help me. The problem is it is showing some error in step 4 while generation of hdl code. 

 function [Rxx]=autom(X)    % [Rxx]=autom(x)
Rxx=zeros(1,1024);
for m=1: 1025
for n=1: 1025-m
Rxx(m)=Rxx(m)+X(n)*X(n+m-1);

end
end

%testbench

N=1024;                            % Number of samples
f1=1;                              % Frequency of the sinewave
FS=200;                            % Sampling Frequency
n=0:1023;                           % Sample index numbers
X=zeros(1,1024);
% X=sin(2*pi*1*(0:1023)/200);
X=sin((2*pi*1.*n)./200);
t=[1:1024]*(1/200);
%ti=f1*n/FS;
%x=sin(2*pi*ti);                    % Generate the signal, x(n) 
%t1=[1:N]; 
%t=t1*(1/FS);                          % Prepare a time axis

subplot(2,1,1);                    % Prepare the figure
plot(t,X);        
title('Sinwave of frequency 1000Hz [FS=8000Hz]');
xlabel('Time, [s]');
ylabel('Amplitude');
grid;

Rxx = autom(X(1:1024));                                % Calculate its autocorrelation
subplot(2,1,2);
plot(Rxx);
title('Autocorrelation function of the sinewave'); % Plot the autocorrelation 
xlabel('lags');
ylabel('Autocorrelation');

Errors i am getting

Ander Biguri
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maudood ahmed
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1 Answers1

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The error says: "[...] unsuported dynamic matrix X[...]"

Your problem is that in your function you are doing X(n)*X(n+m-1); and it seem to be understanding that this is dynamically changing the size of the matrix. I suspect in fact that the error is in Rxx

Note that your X is 1024 on length, but your iterations of n and m are 1025 in length. Rxx is 1024 on length, but you do Rxx(m) and m goes up to 1025, thus dynamically changing its size (MATLAB will increase the size of Rxx from 1024 to 1025, dynamically)

Are you sure you dont want

function [Rxx]=autom(X)    % [Rxx]=autom(x)
Rxx=zeros(1,1024);
for m=1: 1024
  for n=1: 1024-m
    Rxx(m)=Rxx(m)+X(n)*X(n+m-1);
  end
end
Ander Biguri
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  • Sorry but i tried that it didnt work. Can you suggest me some way so that i can get rid of dynamic matrix and get it done somehow as scalar? – maudood ahmed Jul 03 '18 at 10:02
  • @maudoodahmed you dont seem to understand what a dynamic matrix is or what a scalar is. A dynamic matrix is a matrix that changes size. The code I provided makes matrices that are not dynamic. But I dont know much about HDL generation code, so I can not help you more than this, apologies – Ander Biguri Jul 03 '18 at 10:12
  • Ok. Thanks alot. – maudood ahmed Jul 03 '18 at 12:02