function [X,Y,Z] = xyz2XYZ(x,y,z)
  F    = TriScatteredInterp(x,y,z);
  %% 1D x,y,z to 2D X,Y,Z 
  [X,Y]= meshgrid(linspace(min(x),max(x),100), linspace(min(y),max(y),100));  
  Z    = F(X, Y);
end