function V = createVander(v)
%creates Vandermonde Matrix according to formula
%sum_{j=-n}^{n}\alpha_j e^{\landa t_i j}
%vector v should be e^{\landa t_i} with length 2n+1

m=size(v,1);
n=floor(m/2);

B=fliplr(vander(v));
C=vander(1./v);
V=[C(:,n+1:2*n),B(:,1:n+1)];

end