ufl team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

UFL wrote:
> One or more new changesets pushed to the primary ufl repository.
> A short summary of the last three changesets is included below.
>
> changeset:   811:b96d2bbe8284a7255ca510c2fbb35b1445f85a11
> tag:         tip
> user:        "Martin Sandve Alnæs <martinal@xxxxxxxxx>"
> date:        Tue Apr 07 14:50:30 2009 +0200
> files:       doc/manual/chapters/formlanguage.tex ufl/operators.py
> description:
> Added support for this syntax:
>
> x = cell.x
> Df = diff(f, x)
>
> Note that
>   diff(f, x) == grad(f).T

This definition of grad is counter-intuitive to me and likely to lead to 
errors on the part of the users. Why has it been defined this way?

Garth

> because of the way diff is defined.
> Thus diff(f,x) is the same as the FFC grad.
> If we want to change this, it touches a lot
> of places in AD code, so that won't happen now.
>
>
> changeset:   810:26c85777f73b6aefbbfc941917afeee3d9bb1bae
> parent:      809:dda5f025bbd7c50f3c4fb011a09de9f0b086a385
> parent:      808:cbcd4657e7762c62dfb92305b85f8a3fbf6331eb
> user:        "Martin Sandve Alnæs <martinal@xxxxxxxxx>"
> date:        Tue Apr 07 14:40:52 2009 +0200
> files:       
> description:
> merge
>
>
> changeset:   809:dda5f025bbd7c50f3c4fb011a09de9f0b086a385
> parent:      805:6238f8a25e47e1b55dbbf5f52cda4fe22c35c097
> user:        "Martin Sandve Alnæs <martinal@xxxxxxxxx>"
> date:        Tue Apr 07 14:40:43 2009 +0200
> files:       doc/manual/chapters/formlanguage.tex doc/manual/ufl-user-manual.tex
> description:
> Work on manual.
>
> ----------------------------------------------------------------------
> For more details, visit http://www.fenics.org/hg/ufl
>
>
> ------------------------------------------------------------------------
>
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