1. A method, comprising: providing by a device for establishing a model W for emulating a physical quantity P which depends on at least one input parameter x, defining by the device a set X comprising N distinct parameter values x_i for said at least one input parameter x, N being an integer greater than or equal to 1, measuring by the device a first measuring of the physical quantity P, Pm 1 for each of the N distinct parameter values x_i of the at least one input parameter x, while keeping all other input parameters fixed, constructing by the device a Vandermonde matrix VM using said set of N parameter values x_i of said at least one input parameter x, and computing by the device the model W for emulating the physical quantity P based on the Vandermonde matrix and the first measured physical quantity Pm 1 according to the equation W=(VM T *VM) −1 *VM T *Pm 1 .