function s = wire(a,b,d,m)
% s = wire(a,b,d,m)
% Model of simple ideal passive wire 
% a, b :  Vectors [ax ay az] and [bx by bz] of wire end coordinates
% d    :  wire diameter in m  (default = 0.002 m)
% m    :  number of segments  (default: 7)
% s    :  data structure of antenna model 

% Author:  Klaus von der Heide, e-mail:  dj5hg@qsl.net

if nargin<4,   m = 7; end
if nargin<3,   d = 0.002; end

s.st{1}.typ = 'GW';
s.st{1}.pos = [a;b];
s.st{1}.dia = d;
s.st{1}.nsg = m;
s.tl = {};
s.ex = {};
