[Scilab-Dev] floating point operations in different versions of Scilab

[Stéphane Mottelet]

Hello Scilab devmasters !

I have noticed subtle (but real) differences between successive versions 
of Scilab, here's the whole story:

I use fsqp to solve an optimization problem where the computation of the 
cost function and its gradient uses a lot of sparse/full matrix 
products, and I noticed different convergence behaviour of the same code 
depending on the Scilab version.

E.g. with Scilab 5.5.0 and 5.5.1 fsqp converges within the prescribed 
tolerance (norm of the gradient), but with 5.5.2 fsqp stops its 
iterations without reaching it. When relaxing the tolerance successful 
convergence is obtained but I got slightly different results at the end.

I am wondering about which pathway I should follow to identify the 
problem, so my questions are the following :

-is it possible that the scilab version which has been used to compile 
fsqp could produce such a behaviour ?
-did the sparse/sparse and sparse/full product routines change recently ?

Best regards,

S.


-- 
Département de Génie Informatique
EA 4297 Transformations Intégrées de la Matière Renouvelable
Université de Technologie de Compiègne -  CS 60319
60203 Compiègne cedex