Fully adaptive evaluation of sub-band DFT

The (SB-DFT) method is modified to include a band-selection algorithm subband discrete Fourier transform. A new general algorithm is investigated to find the index of the first element in a primary-band. The general adaptive SB-DFT is compared in terms of speed with other partial-band DFT methods. This comparison indicates that the SB-DFT is compared in terms of speed with other partial-band DFT methods. This comparison indicates that the SB-DFT with its generalization and adaptation capabilities is still simpler and faster than other approaches