Why doesn't delaunayTriangulation work on meshgrid input, while delaunay does?

See the code below. delaunayTriangulation(x, y) should also work, or not?

n = 8; 
gv = linspace(0,1,n);
[x, y] = meshgrid(gv);
xv = x(:); yv = y(:);

% Compute the delaunay triangulation
TRI = delaunay(x, y);    % this works!

% TRI = delaunayTriangulation(x, y)    % does not work
TRI = delaunayTriangulation(xv, yv);

[Maxandre Jacqueline]

I would also be interested to know how to combine meshgrid with delaunay triangulation.