On Tue, Jan 8, 2013 at 11:08 AM, w_ang_temp <w_ang_temp at 163.com> wrote:
> 354 KSP preconditioned resid norm 2.882557881065e-01 true resid norm > 3.089426814670e+04 ||r(i)||/||b|| 4.601523777979e-01 > ^^ Notice how this ratio is less than 1.0? DTOL is defined in terms of the smallest residual norm seen. > 355 KSP preconditioned resid norm 2.170676916299e+02 true resid norm > 2.326457175403e+07 ||r(i)||/||b|| 3.465124326697e+02 > 356 KSP preconditioned resid norm 5.764266225925e+00 true resid norm > 6.177943120636e+05 ||r(i)||/||b|| 9.20169 1405543e+00 > 357 KSP preconditioned resid norm 1.701448294063e+04 true resid norm > 1.823554008687e+09 ||r(i)||/||b|| 2.716078947576e+04 > > Linear solve did not converge due to DIVERGED_DTOL iterations 357 > > I cannot understand it. Which one means that the DIVERGED_DTOL > occures:preconditioned resid norm, true resid norm or ||r(i)||/||b||? > What is the difference between preconditioned resid norm and true resid > norm? > It uses the norm that your method is running. In this case, it's the preconditioned norm. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20130108/f26576c5/attachment.html>
