function d = dDistances(x,y,z)

% dDistances - returns a matrix of distances between points
%	d = dDistances(x,y,z)
%	x,y,z - points coordinates matrices with coordinates across column and time along row
%	d     - square matrix of distances between points, or 3D set of square matrices
%		d(i,j) = sqrt( (x(i)-x(j))^2 + (y(i)-y(j))^2 + (z(i)-z(j))^2)
%

n = size(x,1);  % number of points
k = size(x,2);  % number of time samples

d = zeros(n*k,n);
for t = 1:k,
	deltax = x(:,t)*ones(1,n) - ones(n,1)*x(:,t)';
	deltay = y(:,t)*ones(1,n) - ones(n,1)*y(:,t)';
	deltaz = z(:,t)*ones(1,n) - ones(n,1)*z(:,t)';
	d(n*(t-1)+(1:n), 1:n ) = sqrt(deltax.^2 + deltay.^2 + deltaz.^2);
end;

return 
