Re: fft support on octave

[Kai Torben Ohlhus]

On 12/13/19 5:39 PM, niraj pandey wrote:> On Fri, Dec 13, 2019 at 1:19
PM Kai Torben Ohlhus <address@hidden
> <mailto:address@hidden>> wrote:
> 
> 
> 
>     On 12/13/19 3:48 PM, niraj pandey wrote:
>     > On Fri, Dec 13, 2019 at 12:14 PM Kai Torben Ohlhus
>     <address@hidden <mailto:address@hidden>>
>     >> On 12/13/19 3:14 PM, niraj pandey wrote:
>     >>> Hi ,
>     >>>
>     >>> Could you pls help me how to build octave with fft support. I
>     used the
>     >>> following command to build octave but still getting issue.
>     >>>
>     >>>
>     >>> octave:1> fft(0:255)
>     >>> error: fft: support for FFTW was unavailable or disabled when
>     liboctave
>     >>> was built
>     >>>
>     >>>
>     >>> ./configure --prefix=/home/niraj/oc CFLAGS=-fPIC CXXFLAGS=-fPIC
>     >>> --enable-shared --with-gui --with-qt
>     >>> --with-blas=/v5.1.0/BLAS-3.8.0/blas_LINUX.a
>     >>> --with-lapack=/v5.1.0/lapack-3.8.0/liblapack.a --enable-float
>     >>> --enable-sse --with-fftw3-includedir=/tmp/fftw/include/
>     >>> --with-fftw3-libdir=/tmp/fftw/lib
>     >>>
>     >>> Config.log says:   configure:69014: WARNING: FFTW3 library not
>     found.
>     >>> The slower FFTPACK library will be used instead.
>     >>>
>     >>> Thanks
>     >>> Niraj
>     >>
>     >> Dear Niraj,
>     >>
>     >> Still I do not understand why you deploy libraries in the "/tmp"
>     >> directory, which is on usual Linux system a volatile TeMPorary
>     >> directory.  Can't you use your user's /home/niraj directory for all
>     >> libraries instead?  This might be one root of trouble.
>     >>
>     >> Can you describe, how you installed the FFTW3 library on your system?
>     >>
>     >> HTH,
>     >> Kai
>     >>
>     >
>     > Hello Kai,
>     >
>     > I used the following command to install FFTW3.
>     >
>     > ./configure --prefix=/home/niraj/fftw --enable-float --enable-sse
>     >
>     > To install the tool on /tmp area first is just check all the
>     > dependencies required by that tool . Once I identify all the
>     > dependencies I install the tool on production area through some
>     > automated process :)
>     >
>     > Thanks
>     > Niraj
> 
>     Can you submit a small portion of config.log around the error
> 
>     >>> configure:69014: WARNING: FFTW3 library not found.
> 
>     Usually there is a program which is compiled during ./configure and this
>     normally contains the compiler output which might be helpful to get to
>     the root of the trouble.
> 
>     Best,
>     Kai
> 
> 
> Hi Kai,
> 
> PFA config.log files for fftw and octave .
> 
> Thanks
> Niraj
> 


Please always answer below the text.  The interesting portion is this:

$ ./configure --prefix=/home/niraj/oc CFLAGS=-fPIC CXXFLAGS=-fPIC
--enable-shared --with-gui --with-qt
--with-blas=common/pkgs/octave/v5.1.0/BLAS-3.8.0/blas_LINUX.a
--with-lapack=common/pkgs/octave/v5.1.0/lapack-3.8.0/liblapack.a
--enable-float --enable-sse --with-fftw3-includedir=/tmp/fftw/include/
--with-fftw3-libdir=/tmp/fftw/lib

configure:68911: $? = 1
configure:68936: checking fftw3.h usability
configure:68936: gcc -std=gnu11 -c -fPIC -pthread -fopenmp
-I/tmp/fftw/include/  conftest.c >&5
configure:68936: $? = 0
configure:68936: result: yes
configure:68936: checking fftw3.h presence
configure:68936: gcc -std=gnu11 -E -I/tmp/fftw/include/  conftest.c
configure:68936: $? = 0
configure:68936: result: yes
configure:68936: checking for fftw3.h
configure:68936: result: yes
configure:68947: checking for fftw_plan_dft_1d in -lfftw3
configure:68978: gcc -std=gnu11 -o conftest -fPIC -pthread -fopenmp
-I/tmp/fftw/include/  -L/tmp/fftw/lib -L/tmp/fftw/lib
-Wl,-rpath=/tmp/fftw/lib conftest.c -lfftw3  -lm  >&5
/usr/bin/ld: cannot find -lfftw3
collect2: error: ld returned 1 exit status
configure:68978: $? = 1

Is there in `/tmp/fftw/lib` some `libfftw3.so` or is it in
`/tmp/fftw/lib64`?

HTH,
Kai