bugGNU Octave - Bugs: bug #52254, [octave forge] (signal) filtic...


bug #52254: [octave forge] (signal) filtic output not compatible with MATLAB

Submitted by:  None
Submitted on:  Thu 19 Oct 2017 07:01:38 PM UTC  
Category: Octave Forge PackageSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Matlab Compatibility
Status: Need InfoAssigned to: None
Originator Name: Tony RichardsonOriginator Email: -unavailable-
Open/Closed: OpenRelease: 4.2.1
Operating System: Microsoft Windows

Add a New Comment(Rich Markup)

You are not logged in

Please log in, so followups can be emailed to you.


Thu 19 Oct 2017 07:01:38 PM UTC, original submission:

I was getting incorrect results using the filter function. I tracked the issue down to a problem with filtic.

b = [4 -3]; a = [2 -3 1];
filtic(b, a, [0 1])

returns [-1 0] as a result. The correct result (and that returned by MATLAB) is [-0.5 0].

Octave returns the MATLAB result if I divide both b and a by a(1):

b = [4 -3]; a = [2 -3 1];
filtic(b/a(1), a/a(1), [0 1])

gives [-0.5 0].

An easy fix is to divide both vectors by a(1) inside the filtic function, but I am not sure that is the best solution.



(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach File(s):

No files currently attached


Depends on the following items: None found

Items that depend on this one: None found


Carbon-Copy List
  • -unavailable- added by mtmiller (Updated the item)
  • -unavailable- added by None (Submitted the item)

    Do you think this task is very important?
    If so, you can click here to add your encouragement to it.
    This task has 0 encouragements so far.

    Only project members can vote.


    Please enter the title of George Orwell's famous dystopian book (it's a date):



    Follow 2 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Thu 19 Oct 2017 07:10:50 PM UTCmtmillerStatusNone=>Need Info
      Summaryfiltic output not compatible with MATLAB=>[octave forge] (signal) filtic output not compatible with MATLAB

    Back to the top

    Powered by Savane 3.1-cleanup1