bugGNU Octave - Bugs: bug #32836, quiver3 draws nothing, although it...

 
 

bug #32836: quiver3 draws nothing, although it should

Submitted by:  None
Submitted on:  Fri 18 Mar 2011 03:46:29 PM UTC  
 
Category: PlottingSeverity: 3 - Normal
Priority: 5 - NormalItem Group: None
Status: FixedAssigned to: None
Originator Name: Originator Email: -unavailable-
Open/Closed: ClosedRelease: 3.4.0
Operating System: GNU/Linux

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Thu 31 Mar 2011 04:29:12 PM UTC, comment #9:

Patch applied in this changeset (http://hg.savannah.gnu.org/hgweb/octave/rev/4040a95a586d)

Rik <rik5>
Project Administrator
Thu 31 Mar 2011 09:05:10 AM UTC, comment #8:

Works for me, too.

Thanks!

Sebastian Hegler <shegler>
Thu 31 Mar 2011 05:55:34 AM UTC, comment #7:

the fix from comment #6 works for me.
(Fedora 14 x86_64)

Michael Godfrey <godfrey>
Project Member
Thu 31 Mar 2011 05:39:01 AM UTC, comment #6:

I believe I have a fix. I'm attaching a new version of _quiver_.m. Try replacing your existing version with this one. It should go into a directory path like /usr/local/share/octave/3.4.0/m/plot/private/. Please report back if this works.

(file #23062)

Rik <rik5>
Project Administrator
Tue 22 Mar 2011 11:22:12 AM UTC, comment #5:

Please see the new attachment for MATLAB's results.

(file #22986)

Sebastian Hegler <shegler>
Mon 21 Mar 2011 09:23:40 PM UTC, comment #4:

Okay, I think I've found the problem. The scale factor for the length of the arrows is set to zero when only a single point in space is used (with potentially many vectors from said point). Could you run the following in Matlab and post a picture of the results. I need to fine tune the scaling parameters.

Rik <rik5>
Project Administrator
Mon 21 Mar 2011 09:30:23 AM UTC, comment #3:

Okay, here's some sreen shots showing the issue, this time with another quiver3 command:

(file #22976, file #22977)

Sebastian Hegler <shegler>
Fri 18 Mar 2011 07:56:50 PM UTC, comment #2:

Sure, your example exactly marks the problem: If the initial point is identical, nothing is shown. This goes for as many points as you want, for whichever initial point you want.

MATLAB gives the one arrow with two heads that I mentioned.

Anonymous
Fri 18 Mar 2011 07:14:09 PM UTC, comment #1:

Isn't the vector field supposed to be single-valued? I think the problem is that you have specified two values for the vector to draw at the exact same point (0,0,0). If you actually have two points then quiver3 seems to work.

How does Matlab handle this? Does it accept multiple values for the same point?

Rik <rik5>
Project Administrator
Fri 18 Mar 2011 03:46:29 PM UTC, original submission:

Using the following command, I'd expect to see two arrow heads and a closed line between them:

But I see an empty 3D plot window. This is independent of the graphics backend used.

Anonymous

 

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Attach File(s):
   
   
Comment:
   

Attached Files
file #23062:  __quiver__.m added by rik5 (13KiB - text/x-octave)
file #22986:  matlab2.png added by shegler (18KiB - image/png)
file #22976:  matlab.png added by shegler (20KiB - image/png)
file #22977:  octave3.4.0.png added by shegler (16KiB - image/png)

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -unavailable- added by godfrey (Posted a comment)
  • -unavailable- added by shegler (Updated the item)
  • -unavailable- added by rik5 (Posted a comment)
  • -unavailable- added by shegler
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    Follow 10 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Thu 31 Mar 2011 04:29:12 PM UTCrik5StatusReady For Test=>Fixed
      Open/ClosedOpen=>Closed
    Thu 31 Mar 2011 05:39:01 AM UTCrik5Attached File-=>Added _quiver_.m, #23062
      StatusConfirmed=>Ready For Test
    Tue 22 Mar 2011 11:22:12 AM UTCsheglerAttached File-=>Added matlab2.png, #22986
    Mon 21 Mar 2011 09:23:40 PM UTCrik5StatusNeed Info=>Confirmed
    Mon 21 Mar 2011 09:30:23 AM UTCsheglerAttached File-=>Added matlab.png, #22976
      Attached File-=>Added octave3.4.0.png, #22977
    Fri 18 Mar 2011 07:14:09 PM UTCrik5StatusNone=>Need Info
    Fri 18 Mar 2011 03:49:47 PM UTCsheglerCarbon-Copy-=>Added -unavailable-

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