Introduction to fftw
FFTW is a C subroutine library for computing the discrete Fourier
transform (DFT) in one or more dimensions, of arbitrary input size,
and of both real and complex data (as well as of even/odd data,
i.e. the discrete cosine/sine transforms or DCT/DST).
This package is known to build and work properly using an LFS-10.1
platform.
Package Information
User Notes: http://wiki.linuxfromscratch.org/blfs/wiki/fftw
Installation of fftw
Note
We build fftw three times for different libraries in different
numerical precisions: the default double precision floating
point, the older 32-bit (single precision) version named float
which sacrifices precision for speed, and the long double which
offers increased precision at the cost of slower execution.
The first build is for double precision arithmetic. Install
fftw by running the following
commands:
./configure --prefix=/usr \
--enable-shared \
--disable-static \
--enable-threads \
--enable-sse2 \
--enable-avx &&
make
To test the results, issue: make
check. On 32-bit systems, the tests can take
substantially longer than they would on 64-bit machines.
Now, as the root
user:
make install
Now build single precision:
make clean &&
./configure --prefix=/usr \
--enable-shared \
--disable-static \
--enable-threads \
--enable-sse2 \
--enable-avx \
--enable-float &&
make
As the root
user:
make install
Finally, build long double precision:
make clean &&
./configure --prefix=/usr \
--enable-shared \
--disable-static \
--enable-threads \
--enable-long-double &&
make
As the root
user:
make install
Command Explanations
--enable-shared
--disable-static
: Use shared libs instead of static
libs.
--enable-threads
: This
enables libfftw3_threads.so
to be
compiled. It is used by e.g. the gimp plugin from G'MIC.
--enable-float
: This
enables building the library that uses single precision floating
point arithmetic. It is faster but less precise than the default
double precision library. The library will be called libfftw3f.so
needed by PulseAudio-14.2.
--enable-long-double
: This
enables building the library that uses higher precision long-double
floating point arithmetic. The library will be called libfftw3l.so
.