How to add more nulling directions to Phased array pattern synthesis?

Hi,

I'm trying to tune the Matlab example on steering vectors computation for array synthesis nulling on a given direction. The exampe below is from https://es.mathworks.com/help/phased/examples/array-pattern-synthesis.html

My question is, I want to consider only one look direction (thetaad = 0), but multiple interference directions (thetaan = [30 50]). This does not work in the example. Any ideas on how should this be addressed?

Thanks!

c = 3e8;        % signal propagation speed
fc = 1e9;       % signal carrier frequency
lambda = c/fc;  % wavelength

thetaad = -30:5:30;     % look directions
thetaan = 40;           % interference direction

ula = phased.ULA(10,lambda/2);
ula.Element.BackBaffled = true;

% Calculate the steering vector for null directions
wn = steervec(getElementPosition(ula)/lambda,thetaan);

% Calculate the steering vectors for lookout directions
wd = steervec(getElementPosition(ula)/lambda,thetaad);

% Compute the response of desired steering at null direction
rn = wn'*wd/(wn'*wn);

% Sidelobe canceler - remove the response at null direction
w = wd-wn*rn;

% Plot the pattern
pattern(ula,fc,-180:180,0,'PropagationSpeed',c,'Type','powerdb',...
    'CoordinateSystem','rectangular','Weights',w);
hold on; legend off;
plot([40 40],[-100 0],'r--','LineWidth',2)
text(40.5,-5,'\leftarrow Interference Direction','Interpreter','tex',...
    'Color','r','FontSize',10)