[petsc-users] TS snes failure

[Mike Sussman]

Thank you, Matt, for your response.

I am calling TSSolve(), and I am checking all return codes, using
CHKERRQ.

The case I am running is very similar to the ts tutorial example ex2f.F,
re-formulated as a DAE.  I am using TSTHETA.  The line starting
"Timestep =" is from the MyMonitor function in that example.  The line
starting "(DAE)" is my line, printed after the TSSolve() has completed.

For example, I ran a case with 100 time steps, turning on
-snes_converged_reason and -snes_monitor.  The final several steps are:

  46 SNES Function norm 4.129815386097e+00 
   47 SNES Function norm 4.129815386096e+00 
   48 SNES Function norm 4.129815386095e+00 
   49 SNES Function norm 4.129815386095e+00 
   50 SNES Function norm 4.129815386095e+00 
  Nonlinear solve did not converge due to DIVERGED_MAX_IT
Timestep =    99,time =    0.839 sec, error [2-norm] =  1.132E+00, error
[max-norm] =  1.635E+00
    0 SNES Function norm 4.106011479715e+00 
    1 SNES Function norm 4.105987638450e+00 
  Nonlinear solve did not converge due to DIVERGED_LINE_SEARCH
Timestep =   100,time =    0.847 sec, error [2-norm] =  1.144E+00, error
[max-norm] =  1.652E+00
(DAE) Number of time-steps   100 final time   8.4746E-01 solution norm
1.0823E+01

-- 
Mike Sussman