Re: tol, atol and rtol behavior of scipy.sparse.linalg solvers
"Stefan van der Walt" <[email protected]> Mon, 01 May 2023 16:20:33 -0700
| Newsgroups | gmane.comp.python.scientific.devel |
|---|---|
| Message-ID | <[email protected]> |
On Mon, May 1, 2023, at 11:49, Ilhan Polat wrote: > If `atol` is actually set to something, then we return `max(atol, tol*norm(b))`. Why `max` is used I don't understand. > Typically, `atol`, `rtol` pair is used as `tol = atol + rtol*<some metric>`. This is more or less what everybody expects from this pair and their naming is chosen to reflect this. But I'm a bit lost in all the issues I could read. > The first formulation — max(atol, rtol*norm(b)) — is what I'd expect. I.e., you use atol when answers are small, or rtol for larger answers. I'm a bit surprised to see them summed; is this standard? Stéfan _______________________________________________ SciPy-Dev mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/scipy-dev.python.org/ Member address: [email protected]