[casper] Purpose of FFT-Direct

2013-03-12 Thread Ryan Monroe
Hey all, Luke Madden was asking me about what's going on in the FFT-direct today. I'm pretty sure we have basically zero documentation on this lying around, so it's a good time to fix that. I'm going share what I know, but I'd appreciate it if other people could add/correct me as needed.

Re: [casper] Purpose of FFT-Direct

2013-03-12 Thread Aaron Parsons
Hi Ryan, I wrote the various forms of the CASPER FFT, including this one. The broad idea of the architecture was described in: http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4840623tag=1 Basically, (as far as I can tell from the brief perusal of split-radix ffts), I think this *is* a

Re: [casper] Purpose of FFT-Direct

2013-03-12 Thread Ryan Monroe
Hey Aaron! My understanding may be imperfect, but I thought that a split-radix FFT would have a bank of phase rotations (one for each input to fft-direct) after the biplex FFTs. If you chose your phase rotation coefficients correctly, you'd be able to finish the larger FFT with a simple

Re: [casper] Purpose of FFT-Direct

2013-03-12 Thread Aaron Parsons
My understanding may be imperfect, but I thought that a split-radix FFT would have a bank of phase rotations (one for each input to fft-direct) after the biplex FFTs. If you chose your phase rotation coefficients correctly, you'd be able to finish the larger FFT with a simple fft-direct

Re: [casper] Purpose of FFT-Direct

2013-03-12 Thread Ryan Monroe
That makes two of us! Viva la revolution! On 03/12/2013 06:35 PM, Dan Werthimer wrote: it's pretty loud where i'm sitting.

Re: [casper] Purpose of FFT-Direct

2013-03-12 Thread Aaron Parsons
ay dios mio On Tue, Mar 12, 2013 at 6:40 PM, Ryan Monroe ryan.m.mon...@gmail.comwrote: That makes two of us! Viva la revolution! On 03/12/2013 06:35 PM, Dan Werthimer wrote: it's pretty loud where i'm sitting. -- Aaron Parsons 510-306-4322 Hearst Field Annex B54, UCB