[Octave-bug-tracker] [bug #43281] [signal 1.3.0]: filter design function fir2 gives incorrect result

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?43281>

                 Summary: [signal 1.3.0]: filter design function fir2 gives
incorrect result
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Mon 22 Sep 2014 10:38:07 PM UTC
                Category: Octave Forge Package
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Inaccurate Result
                  Status: None
             Assigned to: None
         Originator Name: David Lowenfels
        Originator Email: address@hidden
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 3.8.1
        Operating System: Mac OS

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Details:

the code I ran is the example from the output of `help fir2`


f = [0, 0.3, 0.3, 0.6, 0.6, 1]; m = [0, 0, 1, 1/2, 0, 0];
[h, w] = freqz (fir2 (100, f, m));
 plot (f, m, ";target response;", w/pi, abs (h), ";filter response;");


the resulting graph should be a bandpass filter between 0.3 and 0.6. However
it is between 0 and 0.6.


the same problem happens with fir1 as well (which just called fir2 anyways)
freqz(fir1 (100, [0.3, 0.6]))


I suppose `demo fir2` can also be run to make some erroneous graphs.



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File Attachments:


-------------------------------------------------------
Date: Mon 22 Sep 2014 10:38:07 PM UTC  Name: 9_22_14__3_20_PM.png  Size: 41kB 
 By: None
this is the output graph
<http://savannah.gnu.org/bugs/download.php?file_id=32170>

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