[Scilab-users] spec can crash scilab

[Antoine Monmayrant]

Hello all,

Well, my workaround works up to a certain point.
When I increase the size of the matrix under study, I face another 
blocking issue:

free(): corrupted unsorted chunks

Antoine

On 05/05/2021 09:23, Antoine Monmayrant wrote:
>
> Hello all,
>
> I might have found a workaround, but I still need to ensure that I get 
> exactly the same end results in my code.
> It seems that I can replace:
>
> [W2, gammas] = spec(A); //crashes
>
> by
>
> [al,be,W2]=spec(A,eye(A)); //fine
> gammas=diag(al./be);
>
> If anyone has a solution with eigs, I'll take it.
> Could my workaround help investigate where the bug is in the gateway 
> between scilab and lapack?
>
> Cheers,
>
> Antoine
>
> On 05/05/2021 08:22, Antoine Monmayrant wrote:
>>
>>
>> On 05/05/2021 00:09, Samuel Gougeon wrote:
>>> Le 04/05/2021 à 16:38, Antoine Monmayrant a écrit :
>>>>
>>>> Yes, it does the same
>>>>
>>>> So this bug is still a problem, at least on Ubuntu.
>>>> Can you guys try to run spec.tst on his machine and comment on 
>>>> https://bugzilla.scilab.org/show_bug.cgi?id=15330 ?
>>>>
>>>
>> Hello Samuel,
>>>
>>> Besides, how confusing and messy the notations on the spec () 
>>> documentation page are! ...
>>>
>>>   * R defined twice but differently among arguments
>>>   * L defined among arguments but not used in syntaxes
>>>   * Q and Z used in syntaxes but not described among arguments
>>>   * al, be used in descriptions, instead of alpha and beta listed in
>>>     arguments
>>>   * E used in the description, but not in arguments nor in syntaxes...
>>>
>>> and so on..
>>> In addition, notations differ from a language version to another one...
>>> Some clarification is urgently required.
>> Indeed.
>> It is also a big problem for portability to get such a basic 
>> functionality (solving eigenvalue problems in a linear algebra 
>> software!) only working on some platforms!
>>>
>>> In next release, eigs() -- mainly based on the former Arnoldi 
>>> module, that becomes internal -- is listed in the same help section. 
>>> Have you tried it?
>> Well, I might be a bit far from my field of expertise, but it does 
>> not seem that eigs can compute all the eigenvalues/eigenvectors, does it?
>> It seems that by default it computes the 6 biggest ones and can go up 
>> to rank(A)-2.
>>
>> In my use case, I need all the eigenvalues...
>>
>> Antoine
>>
>>>
>>> Samuel
>>>
>>>
>>> _______________________________________________
>>> users mailing list
>>> users at lists.scilab.org
>>> http://lists.scilab.org/mailman/listinfo/users
>>
>> _______________________________________________
>> users mailing list
>> users at lists.scilab.org
>> http://lists.scilab.org/mailman/listinfo/users
>
> _______________________________________________
> users mailing list
> users at lists.scilab.org
> http://lists.scilab.org/mailman/listinfo/users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.scilab.org/pipermail/users/attachments/20210505/4fb62454/attachment.htm>