[PD] fft beginner question

marius schebella marius.schebella at gmail.com
Thu Nov 22 21:22:54 CET 2007


I try to say, that the results you get from an fft or rfft are the 
cosine and sine portion of the signal (one value per frequency) in the 
frequency domain. (also referred to as real and imag part.
but if you square them, you will not get 1 for each frequency but the 
amplitude.
so cos(f1)^2+sin(f1)^2=amplitude(f1)^2.
marius.

Georg Holzmann wrote:
> marius schebella schrieb:
>> Mathieu Bouchard wrote:
>>
>>> this is actually cos^2+sin^2=1 in this context,
>>
>> these are not unity vextors, if you square the cosine and sine part 
>> you don't get one, but a square of the amplitudes, so it is more 
>> cos^2+sin^2=amplitude^2
> 
> hm, I don't really understand what you try to say here, but cos(x)^2 + 
> sin(x)^2 is 1 !
> 
> LG
> Georg
> 





More information about the Pd-list mailing list