On 03/25/2014 07:04 PM, Robert Cimrman wrote:
Hi Phil,
On 03/25/2014 05:51 PM, seismo_phil wrote:
<snip>
sfepy: nls: iter: 0, residual: 9.332878e+04 (rel: 1.000000e+00)
sfepy: rezidual: 0.00 [s]
sfepy: solve: 0.00 [s]
sfepy: matrix: 0.00 [s]
sfepy: linear system not solved! (err = 5.659775e-10 < 1.000000e-10)
sfepy: nls: iter: 1, residual: 5.748516e-10 (rel: 6.159425e-15)
I'm confused by this, because I thought that this is still a well-posed problem. Can anyone please suggest to me what I may be doing wrong?
The solution is perfectly fine. Look at the sizes of residual norms - the absolute one is about 5e-10, the relative one about 6e-15, which is as close to machine precision in double-precision floats as you can get. The message is just a warning, and it can be prevented by setting the options 'lin_red' or 'eps_a' of the Newton solver to higher values. There is a check that the linear system solution error is smaller than (eps_a * lin_red). Anyway, it almost passes with your settings.
The git version now prints a more helpful warning message that, hopefully, is not that scary :)
r.