A method for the determination of the diffusion tensor anisotropy or the surface energy anisotropy that does not require the formation of particular structures, and that is capable of being performed in cases of moderate-amplitude perturbations. The medium is made by applying an ink using a Meyer Rod which has varying cell lengths along its length. A mirror element is provided, for at least one actuation element in at least one row of actuation elements, including an optically reflecting upper surface, and being vertically suspended over a corresponding actuation element by a mechanically constrained mirror support region that is connected to the corresponding actuation element and that defines a vertical mirror gap. The control determines the selected temperature for cooking to be maintained in the oven cell by averaging selected temperatures sensed by the plurality of temperature sensors in predetermined proportions based on the selected mode of cooking operation.