fig = figure( 1 ) ;
hold on ;
alfa_M = 30 * ( pi / 180 ) ; % radianti
N_rami = 4 ;
alfa   = alfa_M * linspace( -1 , 1 , N_rami ) ;
rho    = 0.75 ;
c      = rho * exp( 1i * alfa ) ;
z0 = 0 ;
r0 = 1i ;
livelli = 6 ;
ramo( z0 , 1i , c , 1 , livelli ) ;
axis equal ;
axis off ;