function out=green( z, x, a, k)% evaluates Green's function for numeric integration% z - integration variable% x - distance between the middle of the segmant and the point in which potential computed% a - radius of the antnna% k - wavenumbers   = size(z,2);		% size of the intup vector xR = ones( 1, s);for m=1:s  R(m) = sqrt( a^2 + (x-z(m))^2);endout = exp(-j*k*R)./(4*pi*R);