- petsc-dev - mailman3.cels.anl.gov

[petsc-dev]Documentation typo: Sign error in SNES Picard defect correction formula
by 李敬都 07 Aug '26

07 Aug '26

Dear PETSc Development Team, I am a researcher using PETSc for numerical simulations of partial differential equations. While reviewing the documentation for the SNES Picard interface, I noticed a sign inconsistency in the defect correction formulation that appears to be a typo. The documentation opens by stating the equation to be solved is: $$A(x)\,x = bp(x) - b$$ However, the provided defect correction iteration is written as: $$A(x^n)(x^{n+1} - x^n) = bp(x^n) + b - A(x^n)x^n$$ Following this, the "classic" Picard iteration is given as: $$A(x^n)x^{n+1} = bp(x^n) + b$$ There is a sign error on the constant term $b$. If we substitute the converged solution $x^*$ into the stated Picard iteration, we obtain $A(x^*)x^* = bp(x^*) + b$, which contradicts the original equation $A(x)x = bp(x) - b$ by a difference of $2b$. The correct defect correction form consistent with the original equation should be: $$A(x^n)(x^{n+1} - x^n) = bp(x^n) - b - A(x^n)x^n$$ which reduces to the correct classic Picard iteration: $$A(x^n)x^{n+1} = bp(x^n) - b$$ I greatly appreciate the high-quality documentation and the extensive work your team has put into PETSc. I wanted to report this small issue to help improve the manual. Please let me know if I have misunderstood the formulation. Best regards, Jingdu Li

2 1

Discussion/vote on no longer putting doc fixes into release branch
by Barry Smith 20 Jul '26

20 Jul '26

I have set up a discussion/vote on changing our docs update policy from release to main. As we are getting close to a release I believe we would benefit from changing the policy now. Please discussion and vote, (this is just an informal vote, not a PETSc council vote) Thanks Barry https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/work_items/1916… Stop making doc changes going forward in release. A discussion and decision. (#1916) · Issues · PETSc / petsc · GitLab gitlab.com

1 0

Re: [petsc-dev] Debugging a Doc Error
by Barry Smith 15 May '26

15 May '26

I found it by looking for corrupt entries in manualpages.cit > On May 15, 2026, at 6:28 PM, Barry Smith <bsmith(a)petsc.dev> wrote: > > You were sloppy when you did something illegal in PETSc :-) > > /*PetscCheck(depth == dim, > > Leaving commented out code in an MR and not ensuring a space after /* for all comments > > > > >> On May 15, 2026, at 5:12 PM, Matthew Knepley <knepley(a)gmail.com> wrote: >> >> Does anyone know how to find out which file is causing this? >> >> https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/jobs/1439627857… <https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/jobs/1439627857…> >> >> I cannot for the life of me decode this error message. >> >> Thanks, >> >> Matt >> >> -- >> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. >> -- Norbert Wiener >> >> https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uC… <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCf…> >

1 0

Re: [petsc-dev] Debugging a Doc Error
by Barry Smith 15 May '26

15 May '26

You were sloppy when you did something illegal in PETSc :-) /*PetscCheck(depth == dim, Leaving commented out code in an MR and not ensuring a space after /* for all comments > On May 15, 2026, at 5:12 PM, Matthew Knepley <knepley(a)gmail.com> wrote: > > Does anyone know how to find out which file is causing this? > > https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/jobs/1439627857… <https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/jobs/1439627857…> > > I cannot for the life of me decode this error message. > > Thanks, > > Matt > > -- > What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. > -- Norbert Wiener > > https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uC… <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCf…>

1 0

Debugging a Doc Error
by Matthew Knepley 15 May '26

15 May '26

Does anyone know how to find out which file is causing this? https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/jobs/1439627857… I cannot for the life of me decode this error message. Thanks, Matt -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uC… <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCf… >

1 0

PETSc/Firedrake Annual Meeting 2026 Registration Deadline April 27th
by Matthew Knepley 15 Apr '26

15 Apr '26

Note that there are two weeks left to register for the PETSc Meeting, and one week to submit an abstract. Key Dates 20 April 2026: Abstract submission deadline *27 April 2026*: Registration deadline Registration is available here: https://urldefense.us/v3/__https://cvent.me/lqGoPm__;!!G_uCfscf7eWS!axmPt7E… 1–3 June 2026: PETSc User Meeting 3–5 June 2026: Firedrake ’26 Meeting We are pleased to announce that the Firedrake Annual Meeting and the PETSc Annual User Meeting will be held jointly this year in Oxford, from Monday 1 June to Friday 5 June. The PETSc meeting will run from Monday morning to Wednesday at noon, followed by the Firedrake meeting, which will begin on Wednesday early afternoon and continue until Friday evening. While we encourage participants to attend both events, registration is available separately for each meeting, or jointly for both. Further information about the event can be found at: https://urldefense.us/v3/__https://petsc.org/release/community/meetings/202… https://urldefense.us/v3/__https://www.firedrakeproject.org/firedrake_26.ht… For any questions, please contact Connor Ward at c.ward20(a)imperial.ac.uk. Thanks, PETSc and Firedrake Teams -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uC… <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCf… >

1 0

Fwd: Reminder: Action Required by April 16 - Important changes for Duo Agent Platform and Duo Core
by Barry Smith 02 Apr '26

02 Apr '26

I’m not sure what the “action required” is but if folks want to try this stuff out go for it. > Begin forwarded message: > > From: GitLab <info(a)gitlab.com> > Subject: Reminder: Action Required by April 16 - Important changes for Duo Agent Platform and Duo Core > Date: April 2, 2026 at 11:00:26 AM EDT > To: bsmith(a)petsc.dev > Reply-To: info(a)gitlab.com > > <https://urldefense.us/v3/__https://email.gitlab.com/dc/3Agyd97uNAM8boMhA7mU… > > > Hi Barry, > > We’re reminding you about an important upcoming change related to Duo Core <https://urldefense.us/v3/__https://email.gitlab.com/MTk0LVZWQy0yMjEAAAGg7a5… >. This is a follow-up from our first email sent on March 3. > > We’re reaching out because your team is using GitLab Duo Chat and Code Suggestions capabilities as part of Duo Core, introduced in the 18.0 release. Use of these capabilities was included free-of-charge to Premium and Ultimate users. > > Starting April 16, 2026, you will no longer have access to “classic” Duo Chat and Code Suggestions as part of Duo Core. > > Instead, your team has upgraded access to agentic chat and improved code suggestions, made available in the 18.8 release with Duo Agent Platform <https://urldefense.us/v3/__https://email.gitlab.com/MTk0LVZWQy0yMjEAAAGg7a5… >. You also now have $12 in included GitLab Credits* per Premium user and $24 in included GitLab Credits* per Ultimate user each month to use on these capabilities as well as other agentic capabilities. > > Duo Agentic Chat is not currently supported in our WebIDEs, but your team can take advantage of the powerful Agentic Chat capabilities in the web UI, IDE extensions (VS Code or JetBrains, Visual Studio for Windows (v0.60.0+), and Duo CLI. See our GitLab Duo Agentic Chat documentation <https://urldefense.us/v3/__https://email.gitlab.com/MTk0LVZWQy0yMjEAAAGg7a5… >for specific instructions on using Duo Agentic Chat via these entry points. > > GitLab Credits is a virtual currency for all AI usage. For example, 50 code suggestions cost one credit. When included credits are exhausted, you can: > > Wait for monthly reset when included credits per user are automatically refreshed. > Accept on-demand billing terms <https://urldefense.us/v3/__https://email.gitlab.com/MTk0LVZWQy0yMjEAAAGg7a5… > to continue using agentic AI capabilities at $1/credit above your included credits. > Pre-purchase a shared pool of credits to share across your team at volume-discounted rates by contacting your account team or directly within Customers Portal <https://urldefense.us/v3/__https://email.gitlab.com/MTk0LVZWQy0yMjEAAAGg7a5… >. > Please reach out to our support team <https://urldefense.us/v3/__https://email.gitlab.com/MTk0LVZWQy0yMjEAAAGg7a5… > with questions about monthly commitments or to discuss platform capabilities based on your usage. > > Please note: There are no changes for GitLab Duo Pro and Duo Enterprise license seat holders. > > * Included credits are per user and refresh monthly. Available for a limited time and subject to change at GitLab's discretion. OSS, EDU, and startup program customers do not receive included credits. > > Here to help, > > The GitLab Team > > <https://urldefense.us/v3/__https://email.gitlab.com/dc/3Agyd97uNAM8boMhA7mU… > > View Web Version <https://urldefense.us/v3/__https://email.gitlab.com/v/MTk0LVZWQy0yMjEAAAGg7… > | Blog <https://urldefense.us/v3/__https://email.gitlab.com/dc/3Agyd97uNAM8boMhA7mU… > | Facebook <https://urldefense.us/v3/__https://email.gitlab.com/MTk0LVZWQy0yMjEAAAGg7a5… > | YouTube <https://urldefense.us/v3/__https://email.gitlab.com/MTk0LVZWQy0yMjEAAAGg7a5… > | LinkedIn <https://urldefense.us/v3/__https://email.gitlab.com/MTk0LVZWQy0yMjEAAAGg7a5… > > GitLab 268 Bush Street, #350, San Francisco, CA 94104, USA > This email was sent to bsmith(a)petsc.dev <mailto:[email protected]>. If you no longer wish to receive these emails you may unsubscribe <https://urldefense.us/v3/__https://page.gitlab.com/UnsubscribePage.html?mkt… > at any time.

1 0

PETSc 3.25 release available
by Barry Smith 31 Mar '26

31 Mar '26

We are pleased to announce the release of PETSc version 3.25.0 at https://urldefense.us/v3/__https://petsc.org/release/download/__;!!G_uCfscf… A list of the major changes and updates can be found at https://urldefense.us/v3/__https://petsc.org/release/changes/325/__;!!G_uCf… The final update to petsc-3.24 i.e petsc-3.24.6 is also available We recommend upgrading to PETSc 3.25.0 soon. As always, please report problems to petsc-maint(a)mcs.anl.gov <mailto:[email protected]> and ask questions at petsc-users(a)mcs.anl.gov <mailto:[email protected]> This release includes contributions from Alex Lindsay Barry Smith Blaise Bourdin Boris Martin Carl von Bonin Claude Opus 4.6 Claude Sonnet 4.6 Connor Ward Cursor David Wells Eric Chamberland Erik Fabrizzi Erik Fabrizzi Han Liu Hansol Suh James Wright Jared Frazier Jed Brown Jeongu Kim Jonas Heinzmann Jose Roman Junchao Zhang Lisandro Dalcin Louis Moresi Mark Adams Martin Diehl Matthew Knepley Miguel Salazar Mr. Hong Zhang Nils Friess Noam T Num Mendez Nuno Nobre Pablo Brubeck Paul Kuehner Pierre Jolivet Richard Tran Mills Ronald Gould Satish Balay sdargavi Stefano Zampini Stephan Kramer Tobin Davis-Jones Toby Isaac Tom Caruso Victor Eijkhout Zach Atkins and bug reports/proposed improvements received from Bahaâ Eddine Sidi Hida Chris Douglas @cmdoug David Knezevic Jin Chen Jose E. Roman Lois Curfman McInnes Mathieu Deuse M Weiland Pierre Jolivet Pierre LEDAC Pim Heeman Stefano Zampini Steven Dargaville Victor Eijkhout Vincent Robert As always, thanks for your support, Barry

1 0

Change last petsc4py rst files to MD?
by Barry Smith 24 Mar '26

24 Mar '26

Lisandro, Would it be too intrusive to change the last of the petsc4py rst files to MD? Barry

1 0

2026 Colorado Conference on Iterative and Multigrid Methods, June 21-26 in Boulder, CO
by Jed Brown 14 Feb '26

14 Feb '26

As Scott announces below, the conference formerly known as Copper will be held in Boulder this June. The student paper competition abstract deadline is Feb 18, with paper submission a week later. We'll have an affordable on-campus housing option. We look forward to your student paper submissions. Registration and lodging will be available soon. https://urldefense.us/v3/__https://coloradoconference.github.io/2026/__;!!G… -------------------- Start of forwarded message -------------------- From: Scott Maclachlan via SIAM <Mail(a)ConnectedCommunity.org> Date: Fri, 6 Feb 2026 17:44:03 +0000 Subject: SIAG on Computational Science and Engineering Community: 2026 Colorado Conference on Iterative and Multigrid Methods To: jed(a)jedbrown.org The Copper Mountain Conference on Multigrid Methods was founded in 1983 and held every two years (odd years) since then. In 1990, the Copper Mountain Conference on Iterative Methods was formed as a companion conference to be held in even years. Together, they are widely regarded as premier international conferences on iterative and multigrid methods. In 2026, we continue this conference series with the Colorado Conference on Iterative and Multigrid Methods to be held on the CU Boulder campus. Abstract submission for the conference will soon open, including for the student paper competition (a tradition at the meeting with a cash award). For more information, see our website at https://urldefense.us/v3/__https://coloradoconference.github.io/2026/__;!!G… Updates will be provided on the web site and in follow-up announcements in the coming weeks. Don't forget to mark your calendars! Important Deadlines: Student Paper Competition (no extensions): Abstract: Wednesday, February 18, 2026 Paper (reserved for students who submit an abstract): Wednesday, February 25, 2026 Presentation Abstracts: Friday, April 3, 2026 Early Registration: Friday, April 17, 2026 ------------------------------ Scott MacLachlan Memorial University of Newfoundland, Canada ------------------------------ Reply to Sender : https://urldefense.us/v3/__https://engage.siam.org/eGroups/PostReply/?Group… Reply to Discussion : https://urldefense.us/v3/__https://engage.siam.org/eGroups/PostReply/?Group… You are subscribed to "SIAG on Computational Science and Engineering Community" as jed(a)jedbrown.org. To change your subscriptions, go to https://urldefense.us/v3/__http://siam.connectedcommunity.org/preferences?s… . To unsubscribe from this community discussion, go to https://urldefense.us/v3/__https://siam.connectedcommunity.org/HigherLogic/… . -------------------- End of forwarded message --------------------

1 0