Firedrake meeting 2020 06 25

Date and time 2020-06-25 15:00UTC (16:00BST)

Action Items

1. Choose someone to minute and chair
2. ALL: (ongoing) triage the open issues and confirm if they are indeed still open (and perhaps provide labels)
3. KS, (DH, LM): Document describing what we think the mixed domain interface should look like (and hence what is needed in UFL, and whether it matches the existing Fenics efforts). Try an alternative description and make previously agreed changes.
4. **: Think about the correct mathematical formulation for Filtered
5. DH: Find time to fix to get final complex sprint test passing. Now passing Continue reviewing
6. **: Add --remove-build-files to make install smaller; convert this to an issue

Minutes

Present: Lawrence Mitchell, David Ham, Jack Betteridge, Koki Sagiyama, Reuben Hill, Matthew Kan, Nacime Bouziani, Stephan Kramer, Sophia Vorderwuelbecke, Tom Gregory, Rob Kirby

Apologies:

Status of Complex Sprint Merge (added by RWH)

What still needs to be done?

DH: Not much still needs to be done.

Action: DH to run through once term is over.

RWH - CSE minisymposterium

Note identical deadlines:

• Deadline for submission of poster abstracts: August 31, 2020 (11:59 p.m. Eastern Time)
• Deadline for submission of minisymposterium proposals: August 31, 2020 (11:59 p.m. Eastern Time) Minisymposterium has to list all poster titles when it is proposed, so poster submissions need to be in already.

Proposed Solution:

RWH will put together Qualtrics survey to be circulated amongst relevant circles ASAP containing minisymposterium title and abstract which will collect poster abstracts which can then be submitted with the final minisymposterium. RWH just needs minisymposterium title, abstract and submission deadline (e.g. August 25th 2020).

Probably need to set deadline for close of play August 30th (since everyone always submits as late as possible).

Action: RWH harass DH about abstract/title.

Tuomas Karna - Equispaced Coordinate Fields (added by RWH)

• Should coordinates be in equispaced function space by default?
• Should FunctionSpace constructor have the variant as an argument?

See https://github.com/firedrakeproject/firedrake/pull/1732

RWH - Should cell_node_map be None for a VertexOnlyMesh?

PyOP2 has an apparently implicit Identity map which would ideally be implemented for a VertexOnlyMesh. To use this you have to set the map argument to None when creating a PyOP2 Arg:

class Arg(object):
    ...
    def __init__(self, data=None, map=None, access=None, lgmaps=None, unroll_map=False):
        ...
        :param map:  A :class:`Map` to access this :class:`Arg` or the default
                     if the identity map is to be used.

How should this be best utilised (if at all)?

Something like an IdentityMap object that takes an iterset and a toset, but has no values.

RWH - Getting FIAT and UFL vertex cell PRs merged

See https://github.com/FEniCS/fiat/pull/41 and https://github.com/FEniCS/ufl/pull/30

FIAT thing looks good: squash+rebase and then prod for approval/merge.

UFL: check change of finiteelementbase.init call.

DHam/MKan

Design of FInAT dual evaluation interface.

What should the right interface look like?

DH:

function : gem.PointSet -> gem # evaluation of expression at points
dual_evaluation : function -> gem

Questions:

1. nodes with derivatives?
2. tensor product elements?/zany elements?
3. should there be a dual basis for finat elements?

Probably want finat-level Functionals so that composition of functionals works properly.

Pull back expressions, or push forward duals?

LM: PETSc is scoping PETSc 4.0

See https://gitlab.com/petsc/petsc/-/issues?label_name%5B%5D=petsc-future

Date of next meeting

2020-06-30 15:00UTC (16:00BST)