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

John Hassler hasslerjc@comcast....
Sat Jul 21 12:21:36 CDT 2012


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.  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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