[Octave-bug-tracker] [bug #65054] inv (Inf (2, 2)) should return matrix of all Inf and rcond of 0

[Rik]

URL:
  <https://savannah.gnu.org/bugs/?65054>

                 Summary: inv (Inf (2,2)) should return matrix of all Inf and
rcond of 0
                   Group: GNU Octave
               Submitter: rik5
               Submitted: Tue 19 Dec 2023 03:31:40 PM PST
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Other
                  Status: In Progress
             Assigned to: rik5
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
                 Release: stable
         Discussion Lock: Any
        Operating System: Any
           Fixed Release: None
         Planned Release: 10.1.0 (current default)


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Follow-up Comments:


-------------------------------------------------------
Date: Tue 19 Dec 2023 03:31:40 PM PST By: Rik <rik5>
For consistency, the inverse of a singular matrix should return all Inf.  For
example,


inv (1e22*ones(2,2))
warning: matrix singular to machine precision
ans =

   Inf   Inf
   Inf   Inf


Currently Octave usually returns all NaN matrix along with an rcond of NaN. 
However, this depends on the version of BLAS being used.  Such a dependency is
undesirable as well as being the wrong result.







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