Rapid solution of parameter-dependent linear systems for electromagnetic problems in the frequency domain

The minimal residual interpolation method reduces the number of iterations in an iterative method for multiple right-hand sides. It uses computed solutions to initialize an iterative solver with an accurate guess. This work demonstrates the efficiency of the method for frequency sweeps and solving scattering problems by plane waves incident from multiple angles. A bound on the number of solutions required for plane wave scattering before the remaining solutions obtained by minimal residual interpolation only is given. We discuss the performance of the method compared to iterative seed techniques. In a numerical example, a reduction factor of 60 is obtained on the number of matrix vector multiplications.