How to tackle the given issue?

I copied the given code from the following Mathworks site: https://www.mathworks.com/help/phased/ref/phased.rootmusicestimator.step.html

clear all;clc
u=[10 4; 45 -2];%u=[Azimuth1 Elevation1; Azimuth2 Elevation2];
% u=[10 4; 45 -2; 65 -8];% 3 Sources
% u=[10 4; 45 -2; 65 -8; 80 0];% 4 Sources
dim=length(u);
M=15;% No. of Antenna Elements
r=1.5;% Radius of UCA
fs = 8000;% Sample rate
fc = 150e6;% Operating frequency
t = (0:1/fs:1).';
x1 = cos(2*pi*t*500);% 1st baseband signal
x2 = cos(2*pi*t*600);% 2nd baseband signal
% x3 = cos(2*pi*t*700);% 3rd baseband signal
% x4 = cos(2*pi*t*800);% 4th baseband signal

%sUCA = phased.UCA('NumElements',M,'Radius',r);% Create UCA Array
sUCA = phased.UCA('NumElements',M,'Radius',r);% Create UCA Array

%x = collectPlaneWave(sUCA,[x1 x2],u',fc);% Plane wave signals
x = collectPlaneWave(sUCA,[x1 x2],u',fc);
%   x = collectPlaneWave(sUCA,[x1 x2 x3],u',fc);% Plane wave signals
%   x = collectPlaneWave(sUCA,[x1 x2 x3 x4],u',fc);% Plane wave signals

%%%%%%%%%%%%%%%%%%%%%%%%%%%%55
% Add random complex Gaussian white noise to the signals.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
rs = RandStream('mt19937ar','Seed',0);
noise = 0.1/sqrt(2)*(randn(rs,size(x))+1i*randn(rs,size(x)));
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5
% Create the phased.RootMUSICEstimator System object™.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
sDOA = phased.RootMUSICEstimator('SensorArray',sUCA,'OperatingFrequency',fc,...
    'NumSignalsSource','Property',...
    'NumSignals',2);%----------------------- (1)-Two signals 

% sDOA = phased.RootMUSICEstimator('SensorArray',sUCA,'OperatingFrequency',fc,...
%     'NumSignalsSource','Property',...
%     'NumSignals',3);%---------------------- (2)-Three signals 

% sDOA = phased.RootMUSICEstimator('SensorArray',sUCA,'OperatingFrequency',fc,...
%     'NumSignalsSource','Property',...
%     'NumSignals',4);%---------------------- (3)-Four signals

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5
% Solve for the azimuth angles for zero degrees elevation.
%%%%%%%%%%%%%%%%%%%%%%%%%%%
elang = 0;
doas = step(sDOA, x + noise, elang);
az = sort(doas)
%%%%%%%%%%%%%%%%%%%%
% Swapping vector b
%%%%%%%%%%%%%%%%%%%%
% [~, ix] = sort(u); % u is my desired vector
% [~, ix1(ix)] = sort(doas);  
% Estimated = doas(ix1);

When I run this code for two signlas, it gives me about correct result i.e., the azimuth angles are estimated correctly in variable az.

Likewise, when I run it for 3 signals, it gives me about the correct result only when I keep the 3rd Elevation angle at -8 in vector u. But when I change its value to say for example -50, then the 3rd angle is estimated wrongly. Why is it so?

Further, when I run it for the four signlas and I keep the 4th Elevation angle at 0 in vector u, then it estimates about the correct results but when I change its value to say for example +40 or -50 etc., it estimates the wrong result. Why is it so also?

[Torsten]

You should ask the author of the code.

[Sadiq Akbar]

Thanks a lot dear Torsten for your kind guidance. But I don't know who is the author? How can I find that author and his email? I thought these are the built-in commands of MATLAB that's why I asked it here.

[Dyuman Joshi]

You should contact MATLAB Support - https://in.mathworks.com/support/contact_us.html?s_tid=hc_trail

[Sadiq Akbar]

Thanks a lot dear Dyuman Joshi for your kind guidance. I tried but I don't understand further what to do and how to do? If you have the email address of some concerned person, kindly let me know so that I can send him in email.

Regards,

[Torsten]

The code seems to be created by the MATLAB staff.

So use the button "Creare Service Request" under

https://uk.mathworks.com/support/contact_us.html?s_tid=hc_trail

and ask your question.

[Sadiq Akbar]

Thank you very much dear Torsten for your kind guidance. I visited the given link. Then I clicked the button "Creare Service Request" . With this, a new page was opend like this(see attachments 1). Next I don't understand what to do because there is no option like "Ask question"? So can you guide me further what to do and how to do it?