FFT > ChirpZ-transform https://en.wikipedia.org/wiki/Chirp_Z-transform .† [信号処理]FFT (Chirp z-変換アルゴリズム) http://d.hatena.ne.jp/yoneh/20080109/1199862684 チャープ Z 変換 https://jp.mathworks.com/help/signal/ug/chirp-z-transform.html Link: DigitalSignalProcessing FFT