AWR1642BOOST: Could I change the number of angle bins for azimuth estimation?

Hi, I currently modified the SDK code of AWR1642 to extract all the 2D range-doppler data for all virutal antennas and send those data through LVDS using DCA1000EVM

the total size of each frames' data is (128(number of range bins) * 16(number of doppler bins) * 8(number of virtual antennas) )

An I am trying to draw range-azimuth heatmap for all virtual antennas and I use range-azimuth static heatmap code from matlab parsing code of mmwdemo

function [Azimuth_Result,Z] =  parse_azim(Q)

% Q(Q>32767) = Q(Q>32767) - 65536;
% Q = 1j*Q(1:2:end)+Q(2:2:end);
Q = reshape(Q, 8, 128);
Q = fft(Q, 64);

theta = asind([-64/2+1 : 64/2-1]'*(2/64));
range = [0:127] * 0.4394;

posX = range' * sind(theta');
posY = range' * cosd(theta');
Azimuth_Result=fftshift(abs(Q),1);
Azimuth_Result=Azimuth_Result.';
Azimuth_Result=Azimuth_Result(:,2:end); 
Azimuth_Result(isnan(Azimuth_Result))=0;
Azimuth_Result(Azimuth_Result<0)=0;


xlin=linspace(-50,50,500);
ylin=linspace(0,70,500);
[X,Y]=meshgrid(xlin,ylin);
warning off
Z=griddata(posX,posY,fliplr(Azimuth_Result),X,Y,'cubic');
Z(end,end)=2000;
Z(Z<0)=0;

figure(2)
surf(xlin,ylin,Z);
zlim([0 inf]);
% axis equal
% % xlabel('Lateral Distance (m)'); ylabel('Longitudinal Distance (m)'); title('Azumuth Heat Map');
shading INTERP
% view(0,90);
% pause(0.1)
% saveas(gcf,['.\picture','Azimuth',num2str(frame),'.png']);
end

From above code, the number of angle bin is set to 64.

If I change the code

Q = fft(Q, 64);

theta = asind([-64/2+1 : 64/2-1]'*(2/64));

to 

Q = fft(Q, 128);

theta = asind([-64/1+1 : 64/1-1]'*(1/64));

Would there be more error for angle estimation, or would it be more accurate for angle estimation?

could the size of angle bin be changed at matlab? or should I change it from c code at sdk?

Thanks,
Regards, 
Jinhyeong