The method is very similar to the transverse shift of a laser beam on the grid presented in this post. In this case, we will rather shift the aperture which is defined by the variable I.mask inside one instance I of the class Interface.

Example:

G1 = Grid(256,0.4);
IM1 = Interface(G1,'RoC',1420,'CA',0.33,'T',0.014);

Offset_X = 0.01;
Offset_Y = 0.03;

IM1.mask = circshift(IM1.mask,[round(-Offset_Y/G1.Step), round(Offset_X/G1.Step)]);
imagesc(G1.Axis,G1.Axis,(IM1.surface-5E-6).*IM1.mask); axis square; colormap gray