Methods and apparatus are provided for modeling of a physical system using two-dimensional look-up tables. A method can include determining coefficients for a piece-wise polynomial function that estimates a non-linear function, storing the coefficients as entries in one or more two-dimensional look up tables in the memory, receiving a complex value input corresponding to an actual input value, identifying two closest entries, a first closest entry and a second closest entry, to the complex input value in a two-dimensional look-up table of the one or more two-dimensional look-up tables, evaluating, using the one or more hardware processors, the piece-wise polynomial function at the complex input value twice, a first evaluation using the coefficients corresponding to the first closest entry and a second evaluation using the coefficients corresponding to the second closest entry, to generate first and second output values, and generating an output value by performing a linear interpolation between the first and second output values.