ADAPTFEKO
ADAPTFEKO is the adaptive frequency utility used to automatically select smaller frequency steps near narrow resonances and larger steps where the results are relatively smooth.
For each frequency, ADAPTFEKO creates a .pre file and calls PREFEKO and the Solver. The file names are derived from the original name plus _fr_n_ada_m where n and m are incremental numerical values (for example, the new files associated with test.pre are test_fr1_ada_1.pre, test_fr1_ada_2.pre, ...).