CHAPTER 6
: Fast Fourier Transform Subroutines
(FFTPACK and VFFTPACK)

This chapter describes the subroutines in FFTPACK and VFFTPACK as they are implemented in the Sun Performance Library. FFTPACK and VFFTPACK are two collections of subroutines to perform Fourier transforms and Fourier synthesis on real and complex data sets.

The first two sections of this chapter describe:

conventions followed in naming arguments and subroutines

extensions to the standard versions of FFTPACK and VFFTPACK.

The remaining sections of this chapter describe the operation of each of the FFT and VFFT subroutines. For each subroutine the interface is shown, the operation of the subroutine is described, and a short FORTRAN 77 program is given with sample output.