I need to port a

fortran program containing the following calls

CALL FFT(X,Y,1,N,1)

CALL FFT(X,Y,1,N,-1)

They are routines from a old version of CERN's genlib we've on our

DEC Station.

Now we're migrating to UNIX so I need to recompile the sources, but the new

version of CERN's libraries contains no more these subroutines.

From the program I deduce:

1) It's real FFT

2) X is the input vector

3) Y is the output vector

4) N is the number of elements

5) 1/-1 means direct/inverse transform

I don't know what the first "1" means.

I tried to substitute it with subroutines from FFTPACK and from Numerical

Recepies. Results of FFTPACK are identic to those of Numerical Recepies, but

they are different from the results I get on VAX: the resulting analisys

diagram is completely useless.

The author is no more reacheable.

Has someone ever used this genlib's FFT? Has someone the CERN's man page

for that old subroutine, so that I can see how to substitute it?

Thank you very much

Kind regards

--Angelo Pagan