SECTION./FINV
FFT/FINVERSE inr ini outr outi
        make inverse discrete Fourier transform
SECTION./FPOW
FFT/FPOWER inr ini outr outi pow_spec
        make discrete Fourier transform and power spectrum
SECTION./FREQ
FFT/FREQUENCY inr ini outr outi
        make discrete Fourier transform with frequency scaling
SECTION./IMAG
FFT/IMAGE inr ini outr outi
	make discrete Fourier transform
SECTION./INVE
FFT/INVERSE inr ini outr outi
	make inverse discrete Fourier transform
SECTION./POWE
FFT/POWER inr ini outr outi pow_spec
	make discrete Fourier transform and power spectrum
