function sPlotPin( x,y,z )
% sPlotPin   - Plots a set of 3D points as pin-heads with pins on z=0 plane
%
%	   sPlotPin( x,y,z )
%      or  sPlotPin( xyz )
%  
%      x,y,z - vectors with x,y and z coordinates of the points
%      xyz   - 3xN or Nx3 matrix of x,y and z coordinates
%

%if length(x) == size(x,2),
%   x=x'; y=y'; z=z';
%end;

if nargin == 1, 
   if size(x,1) == 3, 
       z = x(3,:)'; y = x(2,:)'; x = x(1,:)'; 
   elseif size(x,2) == 3,
       z = x(:,3); y = x(:,2); x = x(:,1); 
   else
       disp('sPlotPin: Wrong number/dimension of parameters');  
       return; 
   end;
end;

x = x(:); y = y(:); z=z(:);


plot3(x,y,z,'o');
H = line([x x]' ,[y y]',[z zeros(size(z))]');
for i = 1:length(H), set(H(i), 'Color', [0 0 0]); end; % black color

return;