1. A method for setting up a control system for a function unit that is parametrized by a plurality of input variables, comprising: selecting a number of value tuples of the input variables as interpolation points from a parameter space defined by the input variables; and determining an interpolation function that is dependent on at least one controlled variable and defines a continuous subspace of the parameter space which has a dimensionality corresponding to the number of controlled variables, and contains every interpolation point.