From eebc4005c6837817bb75e3710a749cd4bb10ffd8 Mon Sep 17 00:00:00 2001 From: wolf Date: Wed, 14 Apr 2004 22:11:37 +0000 Subject: [PATCH] . git-svn-id: https://svn.dealii.org/trunk@9009 0785d39b-7218-0410-832d-ea1e28bc413d --- .../chapter-2.step-by-step/step-15.data/intro.tex | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/deal.II/doc/tutorial/chapter-2.step-by-step/step-15.data/intro.tex b/deal.II/doc/tutorial/chapter-2.step-by-step/step-15.data/intro.tex index 4a1d49268b..b02796cedd 100644 --- a/deal.II/doc/tutorial/chapter-2.step-by-step/step-15.data/intro.tex +++ b/deal.II/doc/tutorial/chapter-2.step-by-step/step-15.data/intro.tex @@ -231,11 +231,12 @@ out of the jump operator. All these details actually matter -- while writing the program I have played around with many settings and different versions of the code, and the result is that if you don't have a good line search, good stopping criteria, the -right metric (scalar product) for the gradient method, and a good refinement -criterion, then the nonlinear solver gets stuck quite readily for this highly -nonlinear problem. Initially, I was hardly able to find solutions for which -the energy dropped below 0.005, while the energy after the final iteration of -the program as it is is usually around 0.0003, and down to 3.5e-5. +right metric (scalar product) for the gradient method, good initial values, +and a good refinement criterion, then the nonlinear solver gets stuck quite +readily for this highly nonlinear problem. Initially, I was hardly able to +find solutions for which the energy dropped below 0.005, while the energy +after the final iteration of the program as it is is usually around 0.0003, +and occasionally down to 3.5e-5. However, this is not enough. In the program, we start the solver on the coarse mesh many times, with randomly perturbed starting values, and while it -- 2.39.5