Hi,
I updated petsc from 3.2 to 3.4. However, I found that the nonlinear solver 
previously worked well now failed with massage DIVERGED_LINE_SEARCH. 
My problem is extremely nonlinear, cubic line search may fail but Newton method 
works.
  
With petsc 3.2, I only use basic Newton by calling 
SNESLineSearchSet(snes, SNESLineSearchNo, PETSC_NULL) 
With 3.4 I call basic Newton by  
SNESLineSearchSetType(snes, SNESLINESEARCHBASIC).

However, petsc 3.4 still reports 
[0] SNESSolve_NEWTONLS(): fnorm=3.7500000000000006e-02, 
gnorm=3.7500000000000006e-02, ynorm=1.0000000000000000e+00, lssucceed=0
[0] SNESNEWTONLSCheckLocalMin_Private(): || J^T F|| 1.414213562373e+00 near 
zero implies found a local minimum  


It seems petsc 3.4 can not disable line search. Does anyone have the same 
problem?

Gong Ding
 


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