Firedrake meeting 2026 06 23

Date and time 2026-06-16 1600 UTC+1

Action Items

1. Pick Chair and Minuter (IM to pick)
2. ALL: (ongoing) triage the open issues and confirm if they are indeed still open (and perhaps provide labels)
3. ALL: do things with SV's branches
4. DH: Email to Andreas to have 2 (+ others!!!) loopy PRs merged TODO: FIND OUT WHICH PRS THESE ARE
5. DH: Talk to GregVernon about PR#2116.
6. JHC: New manual release

Agenda

Present:

Apologies:

CW: Netgen failures

E.g. https://github.com/firedrakeproject/firedrake/actions/runs/28013529584/job/82912184839

How do we fix this for release and main?

LC: dual evaluation for derivative nodes

There are two options:

(easy) approximate the derivatives with finite differences (this will be exact for expressions in the polynomial space). This allows us to write the dual evaluation as a tensor contraction Q_ij f(x_j). Hence this will compose immediately with interpolation in Firedrake (including cross-mesh interpolation)

(hard) compute derivatives of the expression and evaluate those. Will need some minor changes in TSFC. Cross-mesh interpolation will be harder (multiple VOMs, or build a tensor-valued space on the VOM to evaluate all the derivatives)

Merge PRs

• CW: https://github.com/firedrakeproject/firedrake/pull/5143
• CW: https://github.com/firedrakeproject/firedrake/pull/5153
• CW/DS: https://github.com/firedrakeproject/firedrake/pull/5195
• CW: https://github.com/firedrakeproject/firedrake/pull/5196
• CW: https://github.com/firedrakeproject/firedrake/pull/5198
• CW: https://github.com/firedrakeproject/firedrake/pull/5058

Date of next meeting

1600 UTC+0100 2026-06-30