| A subroutine (FFTDC2) coded in Fortran 77 is described, which performs
a Fast Fourier Transform or Discrete Fourier Transform together with necessary
conditioning steps of trend removal, extension, and windowing. The source
code for the entire library of required subroutines is provided with the
digital release of this report. But, there is only one required entry point,
the subroutine call to FFTDC2; all the other subroutines are operationally
transparent to the user. Complete instructions for use of FFTDC2.F (as
well as for all the other subroutines) and some practical theoretical discussions
are included as comments at the beginning of the source code. This subroutine
is intended to be an efficient tool for the programmer in a variety of
production-level signal-processing applications. |
