Hello. I respond myself to say that with Mr.Hofrats help I've found a pckage of fft functions that will work in rt_threads.
The link is ftp://ftp.fsmlabs.at:/pub/rtlinux/math/fft.tar.bz2 It contains various files including a readme which is a good starting point. The fft functions are in fft_mayer.c. Here you can find: fft(n,real,imag),ifft(n,real,imag) which calculates the complex direct and inverse fft transform over the complex vector real+j*imag of n elements. It returns results in the same vectors. It must be noted that ifft gives an unnormalized result so that the execution of ifft(fft(v)) will return same vector v multiplied by the number of points. I haven't used the rest of the functions defined but I guess they work in a similar way. Note that fft_mayer.c includes the header file trigtbl.h (which comes in the package) so make sure you have it in hand when compiling. For copyright info see in fft_mayer.c. Missatge citat per: Miguel Saiz Arnedo <[EMAIL PROTECTED]>: > Hello. > > I need to call fft (fast fourier transform) functions in my rtthreads. I > found > in the internet a packet of fft functions called FFTW which I've been > using in > normal linux without any problems. FFTW uses math functions so you must > be link > your programs with -lm, in addition to -lfftw. > But when I try to call FFTW from rtthreads I get some problems. In > inserting the > module y get some unresolved symbols in functions like malloc, fflush, > free, > exit, stderr, stdout, fprintf, sprintf. Does this mean that FFTW can't > be used > in RTLinux? > Anyway, I can get rid of those unresolved symbols by linking in de C > library > -lc. But I get some new unresolved symbols in --udivdi3, --umoddi3 and > --moddi3 > (this last one isn't new). How can I get rid of those? > If the final conclusion is that I can't use FFTW in rtlinux, does anyone > know > about some pack of fft functions which will work? > > Thanks in advance and best regards. > > Miguel. > -- [rtl] --- > To unsubscribe: > echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR > echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] > -- > For more information on Real-Time Linux see: > http://www.rtlinux.org/ > > -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] -- For more information on Real-Time Linux see: http://www.rtlinux.org/
