% x,y are the cardinal coordinate of the sample pupil positon
% RotAng is used for calculating rotated Zernike standard polynomials
% n is the order of the Zernike standard polynomials

function FFit=PolyFun11n(x,y,RotAng,n)


num=size(x);
if (num(1)<num(2))
    x=x';
    y=y';
    num(1)=num(2);
end

p=sqrt(x.^2+y.^2);
Ang=atan2(y,x)+RotAng;

term=0;
nn=n;


for n=0:1:nn
    for m=0:1:n
        if (mod(n-m,2)==0)
            term=term+1;
            i=0;
            for s=0:(n-m)/2
                i=i+1;
                A=(-1)^s*factorial(n-s);
                B=factorial(s)*factorial((n+m)/2-s)*factorial((n-m)/2-s);
                R(i)=A/B;
                rr(i)=n-2*s;
            end
            tt=i;
     
            FFit(:,term)=zeros(num(1),1);
            if (m==0)
                for k=1:tt
                    FFit(:,term)=FFit(:,term)+sqrt(n+1)*R(k)*(p.^rr(k));
                end
            else
                for k=1:tt
                    FFit(:,term)=FFit(:,term)+sqrt(n+1)*R(k)*(p.^rr(k));
                end
                temp=FFit(:,term);
                FFit(:,term)=sqrt(2)*temp.*sin(m.*Ang);
                if(m>=25)
                    FFit(:,term)=0;
                end
                term=term+1;
                FFit(:,term)=sqrt(2)*temp.*cos(m.*Ang);
                 if(m>=25)
                    FFit(:,term)=0;
                end
            end
        end
    end
end


output(:,1:term)=FFit(:,1:term);
clear FFit;
FFit=output;
return