function acontour(x,y,z,N);
% Last modified 05.08.00
% For Matlab 5.x		 
% File: acontour.m						 
% By Igor Kagan					 
% kigor@tx.technion.ac.il
% http://igoresha.virtualave.net					 
%					 
% Short Description:						 
% Plots arbitrary (not rectangular) contours 
%
% Usage: acontour(xdata, ydata, zdata, NumberOfContourLines) 	 
% Inputs:
% (1) X data
% (2) Y data
% (3) Z data
% (all vectors must be of the same length)
% (4) Number of contour lines 
% Outputs: 
% None

if sum(diff([length(x) length(y) length(z)]))
	errordlg('Vectors must be of the same length!','acontour.m error');
	return;
end

X = unique(x);
Y = unique(y);
Z = zeros(length(Y),length(X));

for k=1:length(z),
	indx = find(X==x(k));
	indy = find(Y==y(k));
	Z(indy, indx) = z(k);
end

contour(X,Y,Z,N);