Dear all, I'm in the configuration where I need to solve a linear system Ax = b where b is very small although not equal to zero.
It appears that, in this configuration, the initial residual of the first iteration of the solver is completely out of reach and the KSP_DIVERGED_DTOL is raised. In particular, when using the "-ksp_monitor_true_residual flag", I get the following : 0 KSP preconditioned resid norm 2.907111674781e+00 true resid norm 1.955854211540e+02 ||r(i)||/||b|| 1.765818923254e+09 What is the best course of action in this case ? Best, Alexandre -- Alexandre This Doctorant CIFRE (Philips Healthcare - INRIA) : Fusion Image / Modèles Numériques pour la quantification de la sévérité de la régurgitation mitrale Master 2 Recherche Mathématiques, Vision, Apprentissage - ENS Cachan Ingénieur spécialisation Santé&Technologie - ECE Paris Bachelor of Science : Informatics - Aalborg University, Danemark tel : 06.32.57.12.44
