View previous topic :: View next topic |
Author |
Message |
southernrocker
Joined: 12 Jan 2005 Posts: 1
|
Posted: Sun Jan 23, 2005 11:55 pm Post subject: Inverse FFTs |
|
|
David,
Just wondering if you came across the DPlot issue on the FFT giving the incorrect phase angle (180 out in the example) with the last DPlot FFT data point?
Seriously, it creates an error that may be significantly reduced in an inverse FFT (if the SW had a switch).
Sincerely,
Joe Dooley |
|
Back to top |
|
|
DPlotAdmin Site Admin
Joined: 24 Jun 2003 Posts: 2310 Location: Vicksburg, Mississippi
|
Posted: Mon Jan 24, 2005 2:46 am Post subject: |
|
|
At present my best answer is this is a consequence of the way the complex numbers are packed into reals by the FFT routines used, and that last phase angle shouldn't be used. Using REALFT (when N is a power of 2) that last phase angle isn't even calculated - it's always 0.
I need a bit more time to look into it, though. _________________ Visualize Your Data
support@dplot.com |
|
Back to top |
|
|
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|