[Octave-bug-tracker] [bug #52904] "mesh" with input array of "logical" type causes Octave to crash

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?52904>

                 Summary: "mesh" with input array of "logical" type causes
Octave to crash
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Mon 15 Jan 2018 10:42:35 PM UTC
                Category: Interpreter
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Segfault, Bus Error, etc.
                  Status: None
             Assigned to: None
         Originator Name: Alexandre
        Originator Email: address@hidden
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.2.1
        Operating System: GNU/Linux

    _______________________________________________________

Details:


case 1, works OK:

mesh(zeros(25,25)); # real data


case 2, one line is enough to make Octave immediately exit without any
warning.

mesh(zeros(25,25)==0); # "logical" array argument


Looks like a crash to me. It's the type of the argument and not its value that
causes the problem.

Expectation: should implicitly convert logical to real, like Matlab does.

My problem didn't arise from a silly experiment; I was rehabilitating some
antique Matlab finite difference code that defined sampling points for an
arbitrary shape, e.g. something like the following:


t=linspace(-1,1,50);
[x,y]=meshgrid(t,t);
z=x+sqrt(-1)*y;
clear t,x,y;
a=(abs(z)<0.8) & (abs(z)>0.3); # mmmm, donuts!
mesh(a+0); % workaround, convert to real


Version:
GNU Octave Version: 4.2.1
Operating System: Linux 4.13.0-26-generic #29~16.04.2-Ubuntu SMP Tue Jan 9
22:00:44 UTC 2018 x86_64

Also tested on Raspbian (Raspberry Pi). Here I get an almost appropriate error
message about invalid "zdata". Should implicitly convert for Matlab
compatibility.

The "contour" function doesn't crash on either Ubuntu or Raspbian, but
displays the zdata error message.





    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?52904>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/