Re: [Dev-C++] Problems with linking FFTW library

[Daniel K. O. <dan...@ya...>]

Cary Haynie wrote:

>Those errors look would suggest that your missing a header file or something.  
>  
>
Actually, it suggests that the lib is missing from the linking stage.

>>I am still getting the same errors even with fftw-2.1.5. version.
>>
>>c:\dev-c++\examples\fft\fft.o(.text+0x29):fft.cpp: undefined reference
>>to `fftw_malloc'
>>    
>>
I didn't test the 2.1.5 version (I don't even know what's a FFT library 
for), but the 3.0.1 binary available at http://www.fftw.org works out of 
the box.
Seems that you aren't linking to the lib. Make sure to put every file in 
its right place. The .h file goes to the include folder, the .dll goes 
to somewhere in your path, and the other files go to your lib folder. 
Then in your project options you have to add the .lib file to the linker 
options.
This (from 
http://www.fftw.org/fftw3_doc/Complex-One_002dDimensional-DFTs.html#Complex-One_002dDimensional-DFTs 
) compiles and runs fine:

---
#include <fftw3.h>

int main(void)
{
        fftw_complex *in, *out;
        fftw_plan p;
        int N=16;

        in = fftw_malloc(sizeof(fftw_complex) * N);
        out = fftw_malloc(sizeof(fftw_complex) * N);
        p = fftw_plan_dft_1d(N, in, out, FFTW_FORWARD, FFTW_ESTIMATE);

        fftw_execute(p); /* repeat as needed */

        fftw_destroy_plan(p);
        fftw_free(in); fftw_free(out);
        return 0;
}
---


Daniel K. O.