[PD] help with rfft~

thewade pdman at aproximation.org
Tue Nov 29 02:49:37 CET 2005

Hi all,

I am reading Curtis Roads book "The Computer Music Tutorial" trying to
understand fft. I get a little lost at times but I think I basically get it.
Now how does this information match with the fft~ or rfft~ object in PD
I wonder?
The help for fft~ says (for that rfft~ at least) the left and right
outputs can be considered as the coefficents of cosine and sine
respectively. Does this mean that if frequency and phase of a sinusoid
can br represented as A*sin(2*PI*f*t)+B*cos(2*PI*f*t), then the left
output of fft~ is B and the right output is A?
If so, how do I get frequency and phase? (My calculus book is back in
If I am going to convolve the two signals - multiply in the frequency
domain - what happens to phase?

I know that I could open the convo-bros patch and copy/paste, but I
would really rather understand the process and write my own patch from

Thank you for the help!
PS: also, for bug reporting purposes: sometimes if I have a patch
running and I open/edit/save an abstraction within that patch i can no
longer close that bastraction as PD claims that there is no .X874598743
object (or some number). And feature requests: i would like to be able
to decare default font size and level of dialogs in the .pdrc. For
example whe I close a window I always get a dialog "are you sure you
want to close this window". I would rather close the window and kick
myself later for not saving, then get that dialog all the time. PD-devel
from CVS

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