Paul Russell wrote:
> mayur.sarode wrote:
>> I am not able to link fftw3 library with my c program
>> c code:
>>
>> #include<stdio.h>
>> #include<fftw3.h>
>> int main()
>> {
>> int i=0;
>> fftw_complex *in,*out;
>> fftw_plan p;
>> fftw_malloc ;
>> int N=100;
>> in=(fft_complex*)fft_malloc(sizeof(fftw_complex) * N);
>> out=(fft_complex*)fft_malloc(sizeof(fftw_complex) * N);
>> for(i=0;i <N;i++)
>>    *(in+i)=i;
>> p = fftw_plan_dft_r2c_1d(N, in, out,FFT_PRESERVE_INPUT);
>> fftw_execute(p);
>> fftw_destroy_plan(p);
>> fftw_free(in);
>> fftw_free(out);
>> for(i=0;i<N;i++)
>> printf("%d \n",out[i]);
>> return(0);
>> }
>>
>>  gcc -lfftw3 -o fft fft.c -L/usr/local/lib
>>
>>
>> output
>> fft.c: In function &lsquo;main&rsquo;:
>> fft.c:15: error: &lsquo;fft_complex&rsquo; undeclared (first use in this
>> function)
>> fft.c:15: error: (Each undeclared identifier is reported only once
>> fft.c:15: error: for each function it appears in.)
>> fft.c:15: error: expected expression before &lsquo;)&rsquo; token
>> fft.c:16: error: expected expression before &lsquo;)&rsquo; token
>> fft.c:18: error: incompatible types in assignment
>> fft.c:19: error: &lsquo;FFT_PRESERVE_INPUT&rsquo; undeclared (first use in this
>> function)
>> fft.c:19: warning: passing argument 2 of &lsquo;fftw_plan_dft_r2c_1d&rsquo; from
>> incompatible pointer type
>>
>> CXan anyone help me out
>>
>>
>>
> 
> gcc -lfftw3 -o fft fft.c -I/usr/local/include -L/usr/local/lib
> 
> Paul

Also note that there are numerous typos, e.g. it should be 
"fftw_malloc", "fftw_complex" and "FFTW_PRESERVE_INPUT".

Paul

mayur.sarode wrote:
> I am not able to link fftw3 library with my c program
> c code:
> 
> #include<stdio.h>
> #include<fftw3.h>
> int main()
> {
> int i=0;
> fftw_complex *in,*out;
> fftw_plan p;
> fftw_malloc ;
> int N=100;
> in=(fft_complex*)fft_malloc(sizeof(fftw_complex) * N);
> out=(fft_complex*)fft_malloc(sizeof(fftw_complex) * N);
> for(i=0;i <N;i++)
>    *(in+i)=i;
> p = fftw_plan_dft_r2c_1d(N, in, out,FFT_PRESERVE_INPUT);
> fftw_execute(p);
> fftw_destroy_plan(p);
> fftw_free(in);
> fftw_free(out);
> for(i=0;i<N;i++)
> printf("%d \n",out[i]);
> return(0);
> }
> 
>  gcc -lfftw3 -o fft fft.c -L/usr/local/lib
> 
> 
> output
> fft.c: In function &lsquo;main&rsquo;:
> fft.c:15: error: &lsquo;fft_complex&rsquo; undeclared (first use in this
> function)
> fft.c:15: error: (Each undeclared identifier is reported only once
> fft.c:15: error: for each function it appears in.)
> fft.c:15: error: expected expression before &lsquo;)&rsquo; token
> fft.c:16: error: expected expression before &lsquo;)&rsquo; token
> fft.c:18: error: incompatible types in assignment
> fft.c:19: error: &lsquo;FFT_PRESERVE_INPUT&rsquo; undeclared (first use in this
> function)
> fft.c:19: warning: passing argument 2 of &lsquo;fftw_plan_dft_r2c_1d&rsquo; from
> incompatible pointer type
> 
> CXan anyone help me out
> 
> 
> 

gcc -lfftw3 -o fft fft.c -I/usr/local/include -L/usr/local/lib

Paul

I am not able to link fftw3 library with my c program
c code:

#include<stdio.h>
#include<fftw3.h>
int main()
{
int i=0;
fftw_complex *in,*out;
fftw_plan p;
fftw_malloc ;
int N=100;
in=(fft_complex*)fft_malloc(sizeof(fftw_complex) * N);
out=(fft_complex*)fft_malloc(sizeof(fftw_complex) * N);
for(i=0;i <N;i++)
   *(in+i)=i;
p = fftw_plan_dft_r2c_1d(N, in, out,FFT_PRESERVE_INPUT);
fftw_execute(p);
fftw_destroy_plan(p);
fftw_free(in);
fftw_free(out);
for(i=0;i<N;i++)
printf("%d \n",out[i]);
return(0);
}

 gcc -lfftw3 -o fft fft.c -L/usr/local/lib


output
fft.c: In function &lsquo;main&rsquo;:
fft.c:15: error: &lsquo;fft_complex&rsquo; undeclared (first use in this
function)
fft.c:15: error: (Each undeclared identifier is reported only once
fft.c:15: error: for each function it appears in.)
fft.c:15: error: expected expression before &lsquo;)&rsquo; token
fft.c:16: error: expected expression before &lsquo;)&rsquo; token
fft.c:18: error: incompatible types in assignment
fft.c:19: error: &lsquo;FFT_PRESERVE_INPUT&rsquo; undeclared (first use in this
function)
fft.c:19: warning: passing argument 2 of &lsquo;fftw_plan_dft_r2c_1d&rsquo; from
incompatible pointer type

CXan anyone help me out