[SciPy-Dev] [SciPy-User] ANN: SciPy 0.11.0 release candidate 1

Ralf Gommers ralf.gommers@googlemail....
Mon Jul 30 15:36:42 CDT 2012


On Sat, Jul 21, 2012 at 7:21 PM, John Hassler <hasslerjc@comcast.net> wrote:

>
> On 7/20/2012 5:00 PM, Pauli Virtanen wrote:
> > 20.07.2012 22:24, John Hassler kirjoitti:
> >> The offending line is:
> >> AA,BB,Q,Z,sdim = qz(A,B,sort=sort)
> >>
> >> I couldn't find 'sort' defined anywhere, so I arbitrarily changed it to
> >> sort='lhp'.  Then it runs, although the test fails.
> >>
> >> Is there something else I can try?
> > Seems to be a problem with the callable sort function then.
> >
> > That it works with sort='lhp' is strange, and probably means that there
> > is not a problem with all callback functions, but something goes wrong
> > in the algorithm. (Which would be expected, if *gees callbacks work
> > without problems.)
> >
> > If you can/know how to recompile, try recompiling with
> >
> > set OPT=-g -DDEBUGCFUNCS
> > python setup.py .........
> >
> > This should make the f2py wrappers spit out extra information on what is
> > going on.
> >
> I'm not set up to recompile.


Is there anyone who can reproduce the issue and investigate this further?
Alternatively I can build some binaries with the above debug flags. I can't
reproduce the issue though, so that may be a painful way to debug.

Ralf



> I set up a little test program to
> reproduce the problem (below).  It leads to the Fortran call to gges in
> _decomp_qz.py.  This crashes if sort_t = 1 (which calls the lambda), but
> not for sort_t = 0.  I didn't play with it any further.
> john
>
> # Test qz
> import numpy as np
> from scipy.linalg import qz
>
> A =   np.array([[3.9,  12.5, -34.5,  -0.5],
>                  [ 4.3,  21.5, -47.5,   7.5],
>                  [ 4.3,  21.5, -43.5,   3.5],
>                  [ 4.4,  26.0, -46.0,   6.0 ]])
>
> B = np.array([[ 1.0,   2.0,  -3.0,   1.0],
>                [1.0,   3.0,  -5.0,   4.0],
>                [1.0,   3.0,  -4.0,   3.0],
>                [1.0,   3.0,  -4.0,   4.0]])
>
>
> #sort = lambda ar,ai,beta : ai == 0  ## crashes
> sort = None                         ## runs
>
> print(qz(A,B,sort=sort))
>
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