What's happening from lines 116-125? xp = zeros (I*J,1); yp = zeros (I*J,1); dp = zeros (I*J,1); for i= [1:1] for j = [1:3] end end k=j+ J* (i-1); xp (k) = x(i); yp (k) = y(j); What's happening on line 128? dp=griddata (xobs, yobs, dobs, xp, yp, 'linear');