Abstract: The invention relates to the determination of a physical property as a function of a n-dimensional domain, with n being a natural number. Values of said physical property correspond to vertices of a n-dimensional first grid that represent the domain. For a set of cells of said first grid, at least one inner point per cell is determined, whereby said inner points, together with the vertices of the first grid, form a respective second grid. Then, for each of said inner points, a corresponding value of the physical property at said inner point is determined, whereby in case a predefined criterion is not fulfilled, said value at the inner point is obtained by performing a measurement.