bugGNU Octave - Bugs: bug #35739, discontinuous derivative from...

 
 

bug #35739: discontinuous derivative from spline w/ 3 points and endpoint derivative

Submitted by:  Keith Lindsay <klindsay>
Submitted on:  Wed 07 Mar 2012 06:17:29 AM UTC  
 
Category: InterpreterSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Incorrect Result
Status: FixedAssigned to: None
Originator Name: Open/Closed: Closed
Release: 3.6.1Operating System: Microsoft Windows

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Sat 19 Apr 2014 01:52:17 AM UTC, comment #9:

This issue has been fixed by other changes to the spline code. The problematic example in this report works fine with Octave version 3.8.0 and later. Closing report.

Rik <rik5>
Project Administrator
Mon 21 Oct 2013 08:07:05 PM UTC, comment #8:

Marco,

This patch of yours missed being applied in the 3.6 release. Do you want to go ahead and commit it for the 3.8 release?

Rik <rik5>
Project Administrator
Mon 04 Jun 2012 09:53:08 PM UTC, comment #7:

Hi,

It appears that the patch that fixes this bug was not incorporated in to the recent 3.6.2 octave release. Do further steps need to be taken to get the patch incorporated?

Thanks,
Keith Lindsay

Keith Lindsay <klindsay>
Tue 10 Apr 2012 01:15:38 PM UTC, comment #6:

Hi Jordi,

no problem this time. But I feel I am still in "D.3 Basics of Generating a Changeset" stage.

Marco

Marco Caliari <caliari>
Project Member
Tue 10 Apr 2012 12:57:44 PM UTC, comment #5:

Marco, you have write access to the Savannah repository. Is there an outstanding problem for why you do not push your own patches?

Jordi GutiƩrrez Hermoso <jordigh>
Project Administrator
Tue 13 Mar 2012 02:49:11 PM UTC, comment #4:

Hg changeset included.

Marco

(file #25357)

Marco Caliari <caliari>
Project Member
Wed 07 Mar 2012 02:23:36 PM UTC, comment #3:

Marco, you seem to have forgotten to attach a patch.

What problems are you facing with creating hg changesets? I would like to help you solve them.

Jordi GutiƩrrez Hermoso <jordigh>
Project Administrator
Wed 07 Mar 2012 02:21:36 PM UTC, comment #2:

The attachment...

(file #25288)

Marco Caliari <caliari>
Project Member
Wed 07 Mar 2012 02:15:43 PM UTC, comment #1:

Dear all,

the enclosed patch works for me. In practice, there is no difference between a complete spline with 3 or more points and so no need to have different cases.

Marco

Fix complete spline with three points (bug #35739)

  • spline.m: Correctly compute the coefficients of a complete

spline with three points. Also add a test to check for this bug.

Marco Caliari <caliari>
Project Member
Wed 07 Mar 2012 06:17:29 AM UTC, original submission:

Hi,

x = 0:.1:2;
pp = spline([0 1 2], [0 0 1 0 0]);
plot(x,ppval(pp,x));

generates a figure with a discontinuous derivative at
x=1, the middle point. The returned piecewise polynomial
has coefs
0 1 0 0
0 1 -2 1

while matlab Version 7.11.0.584 returns
-2 3 0 0
2 -3 0 1

Could this be looked into please?

Thanks,
Keith Lindsay

Keith Lindsay <klindsay>

 

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Attach File(s):
   
   
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Attached Files
file #25357:  spline.diff added by caliari (3KiB - text/x-patch)

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -unavailable- added by rik5 (Posted a comment)
  • -unavailable- added by jordigh (Posted a comment)
  • -unavailable- added by caliari (Posted a comment)
  • -unavailable- added by klindsay (Submitted the item)
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    Follow 6 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Sat 19 Apr 2014 01:52:17 AM UTCrik5StatusPatch Submitted=>Fixed
      Open/ClosedOpen=>Closed
    Tue 10 Apr 2012 07:11:39 AM UTCcaliariStatusNone=>Patch Submitted
    Tue 13 Mar 2012 02:49:11 PM UTCcaliariAttached File-=>Added spline.diff, #25357
    Tue 13 Mar 2012 02:48:30 PM UTCcaliariAttached File#25288=>Removed
    Wed 07 Mar 2012 02:21:36 PM UTCcaliariAttached File-=>Added spline.m.diff, #25288

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