[Octave-patch-tracker] [patch #8535] [signal] firpm (new remez)

[Rob Sykes]

URL:
  <http://savannah.gnu.org/patch/?8535>

                 Summary: [signal] firpm (new remez)
                 Project: GNU Octave
            Submitted by: robsykes
            Submitted on: Sun 14 Sep 2014 06:21:27 GMT
                Category: None
                Priority: 5 - Normal
                  Status: None
                 Privacy: Public
             Assigned to: None
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any

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Details:

This is a new implementation of McClellan-Parks-Rabiner method.
Compared to the current Octave 'remez', it has:

New features:
* Weight per band-edge.
* Simple syntax for amplitude per band.
* Can increase number of iterations.
* Returns minimax error.

Performance improvements:
* Allows longer filters.
* Several times faster.
* Produces more accurate filters.

Other improvements:
* Improved help.
* Demos.

Fewer bugs AFAICT:
  The following filters fail to converge with remez, presumably because of
bugs:

  b=remez(40, [0 .25 .3 .6 .65 1],[0 0 1 1 0 0]);
  b=remez(40, [0 2.5/pi], [0 2.5], 'differentiator');
  b=remez(31, [0 .5 .7 1], [0 0 1 1], 'hilbert');
  b=remez(120, [0 .5 .55 .6 .601 .75 .751 1], [1 1 0 0 0 0 0 0], [1 8 32
64]);

For a speed & accuracy improvements example, try:

tic; b=remez(1500, [0 .0267 .033 1], [1 1 0 0]); toc;[h,f]=freqz(b,1,2^17);
plot(f/pi, 20*log10(abs(h))); axis([0.032 .045 -81.5 -80.5]);

then the same with firpm.




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File Attachments:


-------------------------------------------------------
Date: Sun 14 Sep 2014 06:21:27 GMT  Name: firpm.cc.xz  Size: 13kB   By:
robsykes

<http://savannah.gnu.org/patch/download.php?file_id=32091>

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