n
pi = 4*atan(1);
i = sqrt(-1);
w = exp(2*pi*i/n);
F = <>;
for k = 1:n, for j = 1:n, F(k,j) = w**((j-1)*(k-1));
F = F/sqrt(n);
alfa = r*pi;
rho = exp(i*alfa);
S = log(rho*F)/i - alfa*EYE;
serr = norm(imag(S),1);
S = real(S);
serr = serr + norm(S-S',1)
S = (S + S')/2;
ferr = norm(F-exp(i*S),1)
