configure: WARNING: FFTW3F library not found. The slower FFTPACK library will be used instead

Question

I'm compiling octave on my LFS - Linux from scratch - system.

While configuring octave, I receive a warning:

configure: WARNING: FFTW3F library not found. The slower FFTPACK library will be used instead.

I compiled and installed FFTW 3.3.4, and then reconfigured octave, however I still receive the following messages:

checking fftw3.h usability... yes

checking fftw3.h presence... yes

checking for fftw3.h... yes

checking for fftw_plan_dft_1d in -lfftw3... yes

checking for fftw3.h... (cached) yes

checking for fftwf_plan_dft_1d in -lfftw3f... no

configure: WARNING: FFTW3F library not found. The slower FFTPACK library will be used instead.

I notice that FFTW 3.3.4 installs libfftw3.so but NOT libfftw3f.so, that's why even after installing FFTW 3.3.4, octave cannot find FFTW3F library. Now, I wonder how I can install libfftw3f.so.

Answer 1

It looks like you have the double precision FFTW libraries (libfftw3) but not the single precision versions (libfftw3f). Build it again with:

./configure --enable-float --enable-sse && make install

(assuming we're talking x86 here).

This should then install the libfftw3f libraries next to the existing libfftw3 libs.