From octave-maintainers-request at bevo dot che dot wisc dot edu  Mon Apr 30 18:52:57 2001
Subject: Re: [patch] Use fftw if available
From: Trond Varslot <trond at varslot dot net>
To: Mumit Khan <khan at NanoTech dot Wisc dot EDU>
Cc: octave-maintainers at bevo dot che dot wisc dot edu
Date: Tue, 1 May 2001 01:54:49 +0200

Hello,
I think it would be a great idea to give the option of using FFTW if this is installed on the computer. It should be included in the main octave tree, though, and not distributed as a separate patch. Octave is able to use BLAS and LAPACK. FFTW should be treated the same way.

Now, my problems emerged when trying your patch out. It applies fine, but somehow I get lots of compilation errors of the sort

>/usr/src/build/octave-2.1.33/liboctave/dMatrix.cc:761: undefined reference to `cffti_'
>/usr/src/build/octave-2.1.33/liboctave/dMatrix.cc:764: undefined reference to `cfftf_'
>/usr/src/build/octave-2.1.33/liboctave/dMatrix.cc:776: undefined reference to `cffti_'
>/usr/src/build/octave-2.1.33/liboctave/dMatrix.cc:783: undefined reference to `cfftf_'
>../liboctave/liboctave.a(dMatrix.o): In function `Matrix::ifourier2d(void) const':
>/usr/src/build/octave-2.1.33/liboctave/dMatrix.cc:821: undefined reference to `cffti_'
>/usr/src/build/octave-2.1.33/liboctave/dMatrix.cc:824: undefined reference to `cfftb_'
>/usr/src/build/octave-2.1.33/liboctave/dMatrix.cc:839: undefined reference to `cffti_'
>/usr/src/build/octave-2.1.33/liboctave/dMatrix.cc:846: undefined reference to `cfftb_'
>collect2: ld returned 1 exit status
>make[2]: *** [octave] Error 1
>make[2]: Leaving directory `/usr/src/build/octave-2.1.33/src'
>make[1]: *** [src] Error 2
>make[1]: Leaving directory `/usr/src/build/octave-2.1.33'
>make: *** [all] Error 2

I have not had time to look into what causes these problems, but octave compiles nicely without your patch, so it must be introducing something.
Which version of octave was this patch done against? Which version of fftw did you use? I tried this on octave-2.1.33 with fftw-2.1.3.

I would really like to try it out, as I am currently doing some work which depends rather heavily on fft.


Yours sincerely
Trond Varslot.