详细表述了分数阶傅立叶变换的离散实现，将现有的算法进行比较。-In this note we make a critical comparison of some matlab programs for the digital computation of the

fractional Fourier transform that are freely available and we describe our own implementation that lters

the best out of the existing ones. Two types of transforms are considered: First the fast approximate

fractional Fourier transform algorithm for which two algorithms are available. The method is described

in H.M. Ozaktas, M.A. Kutay, and G. Bozdagi. Digital computation of the fractional Fourier transform.

IEEE Trans. Signal Process., 44:2141{2150, 1996. There are two implementations: one is written by

A.M. Kutay the other is part of package written by J. O Neill. Secondly the discrete fractional Fourier

transform algorithm described in the master thesis C . Candan. The discrete fractional Fourier transform,

Bilkent Univ., 1998 and an algorithm described by S.C. Pei, M.H. Yeh, and C.C Tseng: Digital fractional

Fourier transform based on orthogonal projections IEEE Trans.