Index in position 1 exceeds array bounds (must not exceed 995)

I am trying to plot a TARC and CCL of my MIMO antenna but am getting this errors

> TARC

Index in position 1 exceeds array bounds (must not exceed 995).

Error in TARC (line 23)

S12a=10^(S12(j,2)/20);

Below is the code

%%

%'txt'
S11=dlmread('Mode 1 S11.txt','',2,0);
S12=dlmread('Mode 1 S12.txt','',2,0);
S21=dlmread('Mode 1 S21.txt','',2,0);
S22=dlmread('Mode 1 S22.txt','',2,0);

freq=S11(:,1);
theta=0:30:180;
na = length (S11);
n = length (theta);
Ta = zeros (na,n+1);
Ta(:,1) = freq;
Taa(:,1) = freq;

for i = 1 : n 
    th = theta (i);
    for j = 1 : na 
% if the value of Aa is read from a .txt file (db), you would need to 
% convert it to s2p. format (i.e magnitude) as follows;
        S11a=10^(S11(j,2)/20);
        S12a=10^(S12(j,2)/20);
        S21a=10^(S21(j,2)/20);
        S22a=10^(S22(j,2)/20);
        Ta(j,i+1) = sqrt(((abs(S11a+S12a.*exp(complex(0,1)*th)))^2 + ...
            (abs(S21a+S22a.*exp(1i*th)))^2))/sqrt(2);
        Taa(j,i+1) = 20*log10(Ta(j,i+1));% Converting values back to db

%         Ta(j,i+1) = sqrt(((abs(Aa(j,2)+Aa(j,6).*exp(complex(0,1)*th)))^2 + ...
%             (abs(Aa(j,8)+Aa(j,4).*exp(complex(0,1)*th)))^2))/sqrt(2);
%         Taa(j,i+1) = 20*log10(Ta(j,i+1));% Converting values to db
        
%     Ta(:,i+1) = sqrt(((abs(S11(:,2)+S12(:,2)*exp(1i*th(i)))).^2 + ...
%         (abs(S21(:,2)+S22(:,2)*exp(1i*th(i)))).^2))/sqrt(2);
    
    end
   
end

%%

figure()
plot(freq,Taa(:,2),'-k');
hold
plot(freq,Taa(:,3),'-.b');
plot(freq,Taa(:,4),'.r');
plot(freq,Taa(:,5),':c');
plot(freq,Taa(:,6),'--g');
plot(freq,Taa(:,7),'-m');

dlmwrite('7.txt',Taa,'delimiter','\t')

Answer 1

[Walter Roberson]

na = length (S11);

length() is defined as 0 if the object has any dimension of size 0, and otherwise length is defined as the largest dimension. If a file had 1000 columns and 995 rows, then its length() would be 1000, and trying to iterate to that row number would be a failure.

You should only use length() with something you know to be empty or scalar or a vector; otherwise you should use size() with the appropriate dimension number.

[KALYAN ACHARJYA]

Thanks @Walter Sir

[KALYAN ACHARJYA]

Walter sir comment goes here

"Specify the column offset as 0 (I think it reads the 1 column only), as 0,0 offsets read the first element only."

No, notice the documentation says "starts reading".

Row offset 2 means that it skips two header lines before trying to read numeric data. Column offset 0 means it skips 0 columns out of each line.

There is no problem with those lines, provided that the user really does have exactly two header lines to skip.

Answer 2

[Adamu Halilu Jabire]

Thank you very much mr walter Roberson i got it and the plot is ok

[Kolangiammal S]

Dear mam, thhe following plots use MATLAB code...getting S parameter and different parameters from cst tool.if u have any idea kindly share 1.Envelope corrlate coefficient 2.channel capacity loss ( CCL) 3.mean effective gain 4.multiplexing efficiency Thanks in advance

[Walter Roberson]

If you had asked a new Question when I had suggested two weeks ago, possibly you would have had a response by now. People are not expecting discussion of that topic in this Question about index out of range.

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

Answer 3

[Kolangiammal S]

Dear sir, Good evening. I am working in UWB antenna design. In that I need to plot the following plots use MATLAB code...getting S parameter and different parameters from cst tool.if u have any idea kindly share 1.Envelope correlate coefficient 2.channel capacity loss ( CCL) 3.mean effective gain 4.multiplexing efficiency Thanks in advance

[Walter Roberson]

You should ask a new Question on this topic.

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

Answer 4

[SAROSH AHMAD]

Dear Adamu Halilu Jabire ,

How are you doing>?

Can you also share the Matlab code or way to calculate CCL of the MIMO?

I will be very grateful to you.

Thanks in Advance