[Octave-bug-tracker] [bug #41865] polyeig behavles slightly differently than matlab

[Michael]

URL:
  <http://savannah.gnu.org/bugs/?41865>

                 Summary: polyeig behavles slightly differently than matlab
                 Project: GNU Octave
            Submitted by: mdunphy
            Submitted on: Thu 13 Mar 2014 22:46:57 GMT
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Matlab Compatibility
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 3.8.1
        Operating System: GNU/Linux

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Details:

polyeig.m returns eigenvalues as a diagonal matrix, whereas to be consistent
with MATLAB, it should return the eigenvalues in a vector. Using the test case
in the end of polyeig.m as an example, 


C0 = [8, 0; 0, 4]; C1 = [1, 0; 0, 1];
[v,z] = polyeig (C0, C1);


In MATLAB we get:

>> whos v z
  Name      Size            Bytes  Class     Attributes
  v         2x2                32  double              
  z         2x1                16  double              


In Octave we get:

> whos v z
Variables in the current scope:
   Attr Name        Size                     Bytes  Class
   ==== ====        ====                     =====  ===== 
        v           2x2                         32  double
        z           2x2                         16  double



The fix should be to change

    varargout{1} = v;

to

    varargout{1} = diag (v);

at line 75





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