plumbplot3(X,Y,Z,varargin);

function OUT = plumbplot3(X,Y,Z,varargin);
%PLUMBPLOT3 Plot points in 3D and projection lines onto the XY plane.
%A variation of PLOT3 that draws reference lines or plumb lines.
%   PLUMBPLOT3(X,Y,Z) makes a plumb plot using the default line style.
%   PLUMBPLOT3(X,Y,Z,S) using the line style S (see PLOT).
%
%Example:
% 	X1 = rand(9,1); Y1 = rand(9,1);	Z1 = rand(9,1);  	
%   	X2 = rand(5,5); Y2 = rand(5,5); Z2 = rand(5,5); 
% 	h1 = plumbplot3(X1,Y1,Z1,'bo:');	
%       hold on;
% 	h2 = plumbplot3(X2,Y2,Z2,'r*-.');
%       hold off;

%Written by Daniel P. Dougherty (Oct, 24 1999)
%<[e-mail]>

REPL = get(gca,'NextPlot');

X=X(:);
Y=Y(:);
Z=Z(:);


if (nargin == 4)
	p1 = plot3(X,Y,Z,varargin{1});
	set(p1,'LineStyle','none')
elseif (nargin == 3)
	p1 = plot3(X,Y,Z,'bo');
end

hold on;	
grid on;

A = axis;

if (nargin == 4)
	for i =1:length(X)
		plumb = plot3([X(i) X(i)] ,[Y(i) Y(i)],[A(5) Z(i)],varargin{1});
		set(plumb,'Marker','none');
		if strcmp(get(plumb,'LineStyle'),'none')
			set(plumb,'LineStyle','-');
		end
	end
elseif (nargin == 3)
	for i =1:length(X)
		plot3([X(i) X(i)] ,[Y(i) Y(i)],[A(5) Z(i)],'b-');
	end	
end
hold off;

set(gca,'NextPlot',REPL)
OUT = gca;