COMPUTE FFT

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COMPUTE FFT

            [SIC\]COMPUTE OutVar FFT+|FFT- InVar [REAL]

        FFT+ performs Direct Fast Fourier Transform, while FFT- performs Inverse
        Fast Fourier Transform.

        Command accepts REAL or COMPLEX variables. OutVar is a  2-D  array  with
        second  dimension  equals 2, storing respectively the Real and Imaginary
        part of the (complex) output Fourier transform.  By  default,  InVar  is
        like OutVar, but if parameter REAL is specified InVar is a 1-D array.