Nested for and while loop

I want to generate matrix [a] and I want to the value [a] in while loop.

A=randi(2,2);
b=A*transpose(A);
c=chol(b,'lower');
p=normrnd(0,1,[1,10]);
q=p(p>0); z=q(1:2);
E1=c*transpose(z);
E=transpose (E1);
K=[67.3061 -8.1429;-8.1429 59.1633]
b=[0;4];
for i=1:length(E)
    a(:,:,i)=E(i)*K
    x(:,1)=[0;0];
    n=20;
    r(:,1)=b-a(:,:,i)*x
    d(:,2)=r(:,1)
    k=1;
    while (k<n)
        p=transpose(d(:,k+1))*a(:,:,i)*d(:,k+1)
        q=(transpose(r(:,k))*r(:,k));
        s(k+1)=q/p
        x(:,k+1)=x(:,k)+s(k+1).*d(:,k+1)
        u=a(:,:,i)*d(:,k+1)
        v=s(k+1).*u

        r(:,k+1)=r(:,k)-v
        if r(:,k+1)<=0.001
            break;
        end
        w=transpose(r(:,k+1))*r(:,k+1);
        w1=transpose(r(:,k))*r(:,k);
        c(:,k+1)=w/w1;
        l=d(:,k+1)
        g=(w/w1)*l

        d(:,k+2)=r(:,k+1)+g
        k=k+1;

    end
end

[Dyuman Joshi]

What exactly is the problem that you are facing?