The routines documented here compute discrete Fourier transforms (DFTs) of sequences of real numbers or of Hermitian sequences in either single or double precision arithmetic. The DFTs are computed using a highly-efficient FFT algorithm. Hermitian sequences are represented in a condensed form that is described in Introduction to FFTs. The DFT of a real sequence results in a Hermitian sequence; the DFT of a Hermitian sequence is a real sequence.
Please note that prior to Release 2.0 of ACML the routine ZDFFT/CSFFT and ZDFFTM/CSFFTM returned results that were scaled by a factor 0.5 compared with the currently returned results.