[Octave-bug-tracker] [bug #51657] gausswin produces slightly wrong result

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?51657>

                 Summary: gausswin produces slightly wrong result
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Fri 04 Aug 2017 11:55:32 AM UTC
                Category: Octave Forge Package
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Inaccurate Result
                  Status: None
             Assigned to: None
         Originator Name: Håkon A. Hjortland
        Originator Email: address@hidden
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.0.0
        Operating System: GNU/Linux

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Details:


MATLAB: gausswin(3)' = [0.0439  1.0000  0.0439]
Octave: gausswin(3)' = [0.24935 1.00000 0.24935]

This is less pronounced for normal window lengths, though.

Looking at the algorithms section at
https://www.mathworks.com/help/signal/ref/gausswin.html
it seems that in signal-1.3.2/gausswin.m in the line

w = exp ( -0.5 * ( a/m * [ -(m-1) : 2 : m-1 ]' ) .^ 2 );

the expression a/m should be changed to a/(m-1).





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