[Octave-patch-tracker] [patch #8960] Preliminary balancing and balance option for eig

[Barbara Lócsi]

URL:
  <http://savannah.gnu.org/patch/?8960>

                 Summary: Preliminary balancing and balance option for eig
                 Project: GNU Octave
            Submitted by: bumi
            Submitted on: Tue 29 Mar 2016 10:06:49 PM GMT
                Category: None
                Priority: 5 - Normal
                  Status: None
                 Privacy: Public
             Assigned to: None
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any

    _______________________________________________________

Details:

I started working on preliminary balancing for eig.

I changed the *geev function calls to the extended versions(*geevx) ( in
EIG.cc and fEIG.cc) and implemented checking for 'balance' and 'nobalance'
option (in eig.cc).
The *geevx LAPACK functions would allow 2 more options: permute and scale.
Should these also be implemented?

I already know that in Matlab there is no option to change balance option in
the general case, but the documentation does not mention if the balancing is
default or not in the generalised case. How should I handle this?

I think that balancing a Symmetric or a Hermitian matrix does nothing, so I
didn't touched those functions (so there is no balancing at all). Please
correct me if I am wrong.

I am also not sure what to do in case of an invalid string input. I checked in
some other codes and I am still not sure, in balance it does nothing if it got
an invalid string as second argument, while in matrix_type it causes:
error: matrix_type: Unknown matrix type ...
So I have 2 ideas:
- error / print usage
- don't care continue with the default setting ('balance')

It is also mentioned here: bug #45944 <https://savannah.gnu.org/bugs/?45944>



    _______________________________________________________

File Attachments:


-------------------------------------------------------
Date: Tue 29 Mar 2016 10:06:49 PM GMT  Name: pbeig.diff  Size: 30kB   By: bumi

<http://savannah.gnu.org/patch/download.php?file_id=36797>

    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/patch/?8960>

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