A=[170,70;156,56;180,80;165,65;172,72];
m1=mean(A(:,1));
m2=mean(A(:,2));
A(:,1)=A(:,1)-m1;
A(:,2)=A(:,2)-m2;
C=A'*A;

v=rand(2,1) //initial guess vector

for k = 1:20
    w=A*v;
    lambda=v'*w;
    v=w/norm(w);
end

v

v=v/norm(v);
u=A*v;
u=u/norm(u);
lambda = v'*(C*v)/(v'*v);
s=sqrt(lambda);

P=s*u*v';

P(:,1)=P(:,1)+m1;
P(:,2)=P(:,2)+m2;