[SciPy-user] problems with scipy.test() on Opteron 64-bit
Giovanni Samaey
Giovanni.Samaey at cs.kuleuven.ac.be
Thu Nov 25 08:40:12 EST 2004
Pearu Peterson wrote:
>
>
> On Thu, 25 Nov 2004, Giovanni Samaey wrote:
>
>> What is remarkable is that, the error is the same in the 3 cases.
>> Moreover, if you add up the first two components of array1 you get
>> the first component of array2.
>
>
> It would look like atlas bug but since the same results are obtained
> with Fortran blas/lapack, then I don't know what is happening. I
> presume that
> you did
> rm -rf build
Of course. If I would forget, I would notice that nothing would be
built, anyway...
> What happens when you call geev routine directly? Try for example:
>
> In [1]: import scipy
>
> In [2]: scipy.linalg.flapack.dgeev([[1,2,3],[1,2,3],[2,5,6]],0,0)
> Out[2]:
> (array([ 9.32182538e+00, -6.03426271e-16, -3.21825380e-01]),
> array([ 0., 0., 0.]),
> array([ [ 0., 0., 0.]]),
> array([ [ 0., 0., 0.]]),
> 0)
>
> In [3]: scipy.linalg.flapack.sgeev([[1,2,3],[1,2,3],[2,5,6]],0,0)
> Out[3]:
> (array([ 9.32182503e+00, -2.82419336e-07, -3.21825117e-01],'f'),
> array([ 0., 0., 0.],'f'),
> array([ [ 0., 0., 0.]],'f'),
> array([ [ 0., 0., 0.]],'f'),
> 0)
>
> In [4]: scipy.linalg.calc_lwork.geev('d',3)
> Out[4]: (12, 102)
>
> Is there any difference in your case?
Yes there is; in fact there is a difference in all three.
In[1]: import scipy
In[2]: scipy.linalg.flapack.dgeev([[1,2,3],[1,2,3],[2,5,6]],0,0)
Out[2]: (array([ 9.43719064, -0.11536526, -0.32182538]),
array([ 0., 0., 0.]),
array([ [ 0., 0., 0.]]),
array([ [ 0., 0., 0.]]),
0)
In[3]: scipy.linalg.flapack.sgeev([[1,2,3],[1,2,3],[2,5,6]],0,0)
Out[3]: (array([ 0., 0., 0.],'f'),
array([ 0., 0., 0.],'f'),
array([ [ 0., 0., 0.]],'f'),
array([ [ 0., 0., 0.]],'f'), 3)
In[4]: scipy.linalg.calc_lwork.geev('d',3)
Out[4]: (12, 174)
Giovanni
>
> Pearu
>
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--
Giovanni Samaey http://www.cs.kuleuven.ac.be/~giovanni/
Katholieke Universiteit Leuven email: giovanni at cs.kuleuven.ac.be
Departement Computerwetenschappen phone: +32-16-327081
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