bugGNU Octave - Bugs: bug #43511, null array retained when cellstr...


bug #43511: null array retained when cellstr is used to build vector through concatenation

Submitter:  None
Submitted:  Fri 31 Oct 2014 10:02:14 PM UTC
Category:  Interpreter Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Regression
Status:  Fixed Assigned to:  lachlan
Originator Name:  Kelvin McCollough Originator Email:  -email is unavailable-
Open/Closed:  * Closed Release:  * dev
Operating System:  * Any
* Mandatory Fields

Add a New Comment (Rich Markup)

Comment Type & Canned Response:


( Jump to the original submission )

Mon 15 Feb 2016 06:47:56 PM UTC, comment #11: 

I committed the patch here.

I changed

if (p->dims ().zero_by_zero ())


if (p->is_empty ())

because it seems that any empty matrix should be suppressed and that

a = 'example';
b = zeros (2,0);
b = [b, cellstr(a)]
b => 'example';

It also created a failing test in copyobj.m.  That seems to have been potentially unclear coding that was vulnerable to the change in definition.  I fixed that too.

Rik <rik5>
Project Administrator
Mon 08 Feb 2016 06:53:04 PM UTC, comment #10: 

I've tested it and reported / edited the bug overview you and Avinoam made in the wiki some day ago. AFAIR it worked well.
I didn't push yet due to lack of time (testing is one thing, can be done in between, but with pushing I always try to be extra cautious)

Did I understand well that you've been given push credentials? If so, congratulations! very well.
(and if not so, it would be about time you would get it IMO)

Philip Nienhuis <philipnienhuis>
Project Member
Tue 26 Jan 2016 04:54:49 AM UTC, comment #9: 

The attached patch fixes the problem reported.

It makes constructs such as [ [], {1}; {2}, {3} ] illegal, since the rows have different numbers of elements.  I assume that is the desired behaviour.

(file #36166)

Lachlan Andrew <lachlan>
Fri 20 Nov 2015 01:47:49 PM UTC, comment #8: 

This also occurs in the released Octave 4.0.0

Thu 19 Mar 2015 10:01:13 PM UTC, comment #7: 

Matlab r2015a behaves the same as r2012a.

Philip Nienhuis <philipnienhuis>
Project Member
Sat 08 Nov 2014 10:36:00 PM UTC, comment #6: 

Sure, here is the result:

>> [ [], {1}, [], {2}, [] ]

ans =

    [1]    [2]

>> ver
MATLAB Version: (R2012a)

I've marked it as a regression :-)

Philip Nienhuis <philipnienhuis>
Project Member
Fri 07 Nov 2014 03:57:53 PM UTC, comment #5: 

Well, at least the behavior seems to be generalized to concatenation with any cell.

@Philip: Could you make one more test?  I don't think the first entry is special, but I want to verify that Matlab removes all null matrices wherever they appear in the list.

The following example in the development version of Octave produces:

[ [], {1}, [], {2}, [] ]
ans =
  [1,1] = [](0x0)
  [1,2] =  1
  [1,3] = [](0x0)
  [1,4] =  2
  [1,5] = [](0x0)

Under Octave 3.4.3 it produces

[ [], {1}, [], {2}, []]
ans =
  [1,1] =  1
  [1,2] =  2

If Matlab is the same as 3.4.3 then I think we should mark this bug as a regression.

Rik <rik5>
Project Administrator
Fri 07 Nov 2014 12:13:33 PM UTC, comment #4: 

Forgot (comment #3): r2012a 32-bit

Philip Nienhuis <philipnienhuis>
Project Member
Fri 07 Nov 2014 12:13:06 PM UTC, comment #3: 

Yes it does strip it out.
(I can't copy results verbatim, as my ML prerelease timed out and I ran the commands in passing while being logged in remotely at work.)

Philip Nienhuis <philipnienhuis>
Project Member
Mon 03 Nov 2014 04:28:22 AM UTC, comment #2: 

I don't think there is any difference between cellstr and regular cells arrays, but could someone check the following concatenation in Matlab?

a = 1;
b = [];
c = [b, {a}]

Does this also strip out the null matrix b?

Rik <rik5>
Project Administrator
Fri 31 Oct 2014 10:11:41 PM UTC, comment #1: 

Matlab r2014b prerelease does (empty lines removed):

>> a = 'example'
a =
>> b = []
b =
>> b = [b cellstr(a)]
b =

...so yes, Octave (just checked in 4.1.0+ too) behaves at least ML-incompatible.

Release => dev, OS => any, title (Summary) adapted a little

Philip Nienhuis <philipnienhuis>
Project Member
Fri 31 Oct 2014 10:02:14 PM UTC, original submission:  

octave:14> a = "example"
a = example
octave:15> b = []
b = [](0x0)
octave:16> b = [b, cellstr(a)]
b =
  [1,1] = [](0x0)
  [1,2] = example

Version 3.4.3 and older matlab versions would return

octave:62> a = "example"
a = example
octave:63> b = []
b = [](0x0)
octave:64> b = [b, cellstr(a)]
b =
  [1,1] = example
octave:65> version
ans = 3.4.3



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

Attach Files:

Attached Files
file #36166:  bug_43511.cset added by lachlan (1KiB - application/octet-stream)


Depends on the following items: None found

Items that depend on this one: None found


Carbon-Copy List
  • -email is unavailable- added by lachlan (Updated the item)
  • -email is unavailable- added by rik5 (Posted a comment)
  • -email is unavailable- added by None (Submitted the item)

    There are 0 votes so far. Votes easily highlight which items people would like to see resolved in priority, independently of the priority of the item set by tracker managers.

    Only project members can vote.





    Follow 11 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2016-02-15 rik5 StatusPatch Submitted Fixed
        Open/ClosedOpen Closed
    2016-02-08 lachlan Assigned toNone lachlan
    2016-02-08 lachlan StatusConfirmed Patch Submitted
    2016-01-26 lachlan Attached File- Added bug_43511.cset, #36166
    2014-12-06 rik5 Summarynull arrary retained when cellstr is used to build vector through concatenation null array retained when cellstr is used to build vector through concatenation
    2014-11-08 philipnienhuis Item GroupMatlab Compatibility Regression
    2014-10-31 philipnienhuis StatusNone Confirmed
        Release3.8.2 dev
        Operating SystemGNU/Linux Any
        Summarynull arrary to be retained when cellstr is used to build vector through concatenation null arrary retained when cellstr is used to build vector through concatenation

    Back to the top

    Powered by Savane 3.9