I need some help with a simple delay and sum linear array beamforming code

This is my code so far. I need it to work for beam steering. What should I do?

clc close all

ANGLE_RESOLUTION= 500; % // Number of angle points to calculate

    numElements = 4;    %// Number of array elements
    spacing = 0.2;      %// Element separation in metres
    freq = 1000.0;      %// Signal frequency in Hz 
    %Fs=40000;
    %f=freq/Fs;
   speedSound = 343.0;  %// m/s

array=[];
 for a=1:ANGLE_RESOLUTION
     angle = -90 + 180.0 * a / (ANGLE_RESOLUTION-1);
     angleRad = pi * angle / 180;
     realSum = 0;
    % imagSum = 0;

      for i=1 : numElements
         position = i * spacing;
         delay = position * sin(angleRad) / speedSound;         
         realSum =realSum+ cos(2.0 * pi * freq * delay);
       %  imagSum =imagSum+ sin(2.0 * pi * freq * delay);
      end;

       output = sqrt(realSum * realSum  ) / numElements;

     logOutput(a) = 20 * log10(output);
      if (logOutput < -50)
          logOutput = -50;     
      end;
    array=[array logOutput(a)];
   end;

Answer 1

[deepthy sivan]

angle = -90 + 180.0 * a / (ANGLE_RESOLUTION-1);

why doing this?