Andras,
It's a little more complicated than that; balancing is always done in octave for the
standard (one matrix) nonsymmetric eigenvalue problem because dgeev always
does balancing. The generalized eigenvalue problem on the other hand never does
balancing because dggev does not balance.
In order to add the 'nobalance' option to octave to make it more compatible
with ML it would be necessary to use dgeevx in place of dgeev which does not
have the option to turn off balancing. Likewise to add balancing to the generalized
problem it would be necessary to change dggev to dggevx. These are in
liboctave/numeric/EIG.cc
The example shown in the ML doc
in which 'nobalance' is necessary gives incorrect results in octave when
octave is built with lapack versions prior to 3.5, but gives correct results
when octave is built with 3.5, so it appears the new balancing algorithm works
for this example. It would be interesting to try it with larger examples, say from
and difficult balancing cases should be added to the test cases for the
standard and generalized eigenvalue problems.