[Octave-bug-tracker] [bug #49026] function fft return wrong result or crash if n=1 and dim>2

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?49026>

                 Summary: function fft return wrong result or crash if n=1 and
dim>2
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Thu 08 Sep 2016 05:36:07 AM UTC
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: address@hidden
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.0.3
        Operating System: GNU/Linux

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Details:

wrong result:

octave:1> x=rand(3,4,2), fft(x,1,3)
x =

ans(:,:,1) =

   0.017138   0.462852   0.363441   0.922481
   0.140206   0.042190   0.956938   0.162861
   0.116520   0.675517   0.028859   0.152628

ans(:,:,2) =

   0.3657579   0.5745495   0.1027223   0.4093351
   0.9649254   0.7427751   0.0049076   0.5797570
   0.9617079   0.3918733   0.6584627   0.9648994

ans =

   0   0   0   0
   0   0   0   0
   0   0   0   0

octave:2> x=rand(2,4,1,2), fft(x,1,4)
x =

ans(:,:,1,1) =

   0.25452   0.96034   0.12719   0.37965
   0.35650   0.90113   0.25084   0.62313

ans(:,:,1,2) =

   0.49780   0.79052   0.71106   0.28961
   0.23440   0.68358   0.77451   0.79083

ans = [](0x0)



crash:

octave:1> x=rand(2,4,2,2), fft(x,1,4)
x =

ans(:,:,1,1) =

   0.2503632   0.9714970   0.7993745   0.0039809
   0.6455604   0.8834564   0.9793053   0.2731584

ans(:,:,2,1) =

   0.82234   0.84438   0.22820   0.52942
   0.71028   0.34665   0.24366   0.80572

ans(:,:,1,2) =

   0.589032   0.046873   0.646299   0.279528
   0.072980   0.606222   0.339875   0.582812

ans(:,:,2,2) =

   0.16773   0.22497   0.50414   0.44783
   0.95144   0.84045   0.29088   0.78029

panic: Floating point exception -- stopping myself...
attempting to save variables to 'octave-workspace'...
save to 'octave-workspace' complete


octave:1> x=rand(1,4,2,2), fft(x,1,4)
x =

ans(:,:,1,1) =

   0.991429   0.046931   0.686220   0.749211

ans(:,:,2,1) =

   0.13584   0.96292   0.59547   0.51085

ans(:,:,1,2) =

   0.903782   0.350536   0.011354   0.730583

ans(:,:,2,2) =

   0.97086   0.55458   0.90932   0.18700

panic: Floating point exception -- stopping myself...
attempting to save variables to 'octave-workspace'...
save to 'octave-workspace' complete


my version:

octave:1> ver
----------------------------------------------------------------------
GNU Octave Version: 4.0.3
GNU Octave License: GNU General Public License
Operating System: Linux 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u1
(2016-09-03) x86_64
----------------------------------------------------------------------
no packages installed.



ii  liboctave3:amd64                      4.0.3-1~bpo8+1                      
amd64        Shared libraries of the GNU Octave language
ii  octave                                4.0.3-1~bpo8+1                      
amd64        GNU Octave language for numerical computations
ii  octave-common                         4.0.3-1~bpo8+1                      
all          architecture-independent files for octave
ii  octave-doc                            4.0.3-1~bpo8+1                      
all          PDF documentation on the GNU Octave language
ii  octave-info                           4.0.3-1~bpo8+1                      
all          GNU Info documentation on the GNU Octave language





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