fftw unable to compile

[superutsav]

Hi,

I've downloaded and installed fftw 3.0.1 ( on Mandrake 10, AMD athlon). Now, i am unable to compile any programs using fftw...
I am including the header file <fftw3.h> ion the program.
On running gcc, the compiler throws back this :

/home/utsav/tmp/ccsMtd04.o(.text+0x1a): In function `main':
: undefined reference to `fftw_malloc'
/home/utsav/tmp/ccsMtd04.o(.text+0x2d): In function `main':
: undefined reference to `fftw_malloc'
/home/utsav/tmp/ccsMtd04.o(.text+0x79): In function `main':
: undefined reference to `fftw_plan_dft_1d'
/home/utsav/tmp/ccsMtd04.o(.text+0x8a): In function `main':
: undefined reference to `fftw_execute'
/home/utsav/tmp/ccsMtd04.o(.text+0xe2): In function `main':
: undefined reference to `fftw_destroy_plan'
/home/utsav/tmp/ccsMtd04.o(.text+0xf0): In function `main':
: undefined reference to `fftw_free'
/home/utsav/tmp/ccsMtd04.o(.text+0xfe): In function `main':
: undefined reference to `fftw_free'
collect2: ld returned 1 exit status

/home/utsav/tmp/ccsMtd04.o(.text+0x1a): In function `main':
: undefined reference to `fftw_malloc'
/home/utsav/tmp/ccsMtd04.o(.text+0x2d): In function `main':
: undefined reference to `fftw_malloc'
/home/utsav/tmp/ccsMtd04.o(.text+0x79): In function `main':
: undefined reference to `fftw_plan_dft_1d'
/home/utsav/tmp/ccsMtd04.o(.text+0x8a): In function `main':
: undefined reference to `fftw_execute'
/home/utsav/tmp/ccsMtd04.o(.text+0xe2): In function `main':
: undefined reference to `fftw_destroy_plan'
/home/utsav/tmp/ccsMtd04.o(.text+0xf0): In function `main':
: undefined reference to `fftw_free'
/home/utsav/tmp/ccsMtd04.o(.text+0xfe): In function `main':
: undefined reference to `fftw_free'
collect2: ld returned 1 exit status

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What am i doing wrong???

Thanks
superutsav

[jacek]

Did you add "-lfftw" to tell gcc that you want to link with fftw?

[wysota]

You're not linking with the library. Add "-lfftw" (or something like that) to your linker flags.

[superutsav]

Thanks for the -lfftw thing...
However, i now have a new error:

/usr/bin/ld: cannot find -lfftw
collect2: ld returned 1 exit status

/usr/bin/ld: cannot find -lfftw
collect2: ld returned 1 exit status

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superutsav

[wysota]

Thanks for the -lfftw thing...
However, i now have a new error:

/usr/bin/ld: cannot find -lfftw
collect2: ld returned 1 exit status

/usr/bin/ld: cannot find -lfftw
collect2: ld returned 1 exit status

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locate libfftw
and add -L with a directory where it resides
And check if it is libfftw or libfftw3, maybe you just need to change "-lfftw" to "-lfftw3"

[superutsav]

Hey... Thanks again... this time, however, there's yet another error, and i think this is an intrinsic fftw error:

/usr/local/lib/libfftw3.a(trig1.o)(.text+0xb9): In function `fftw_sincos':
: undefined reference to `cos'
/usr/local/lib/libfftw3.a(trig1.o)(.text+0xe5): In function `fftw_sincos':
: undefined reference to `sin'
collect2: ld returned 1 exit status

/usr/local/lib/libfftw3.a(trig1.o)(.text+0xb9): In function `fftw_sincos':
: undefined reference to `cos'
/usr/local/lib/libfftw3.a(trig1.o)(.text+0xe5): In function `fftw_sincos':
: undefined reference to `sin'
collect2: ld returned 1 exit status

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What can i do about this?
superutsav

[jacek]

: undefined reference to `cos'
[...]
What can i do about this?

You are not linking your program with maths library ("-lm").

[superutsav]

Thanks guys...
That was an awesome quick reply... the fastest i've ever got on a forum
problem solved ... thanks
superutsav