Changes in version 2016.2.0¶
FIAT 2016.2.0 was released on 2016-11-30.
Summary of changes¶
- More elegant edge-based degrees of freedom are used for generalized Regge finite elements. This is a internal change and is not visible to other parts of FEniCS.
- The name of the mapping for generalized Regge finite element is changed to “double covariant piola” from “pullback as metric”. Geometrically, this mapping is just the pullback of covariant 2-tensor fields in terms of proxy matrix-fields. Because the mapping for 1-forms in FEniCS is currently named “covariant piola”, this mapping for symmetric tensor product of 1-forms is thus called “double covariant piola”. This change causes multiple internal changes downstream in UFL and FFC. But this change should not be visible to the end-user.
- Added support for the Hellan-Herrmann-Johnson element (symmetric matrix fields with normal-normal continuity in 2D).
- Add method
FiniteElement.is_nodal()
for checking element nodality - Add
NodalEnrichedElement
which merges dual bases (nodes) of given elements and orthogonalizes basis for nodality - Restructuring
finite_element.py
with the addition of a non-nodal classFiniteElement
and a nodal classCiarletElement
.FiniteElement
is designed to be used to create elements where, in general, a nodal basis isn’t well-defined.CiarletElement
implements the usual nodal abstraction of a finite element. - Removing
trace.py
andtrace_hdiv.py
with a new implementation of the trace element of an HDiv-conforming element:HDivTrace
. It is also mathematically equivalent to the formerDiscontinuousLagrangeTrace
, that is, the DG field defined only on co-dimension 1 entities. - All nodal finite elements inherit from
CiarletElement
, and the non-nodalTensorProductElement
,EnrichedElement
andHDivTrace
inherit fromFiniteElement
.
Detailed changes¶
- Enable Travis CI on GitHub
- Add Firedrake quadrilateral cell
- Add tensor product cell
- Add facet -> cell coordinate transformation
- Add Bubble element
- Add discontinuous Taylor element
- Add broken element and H(div) trace element
- Add element restrictions onto mesh entities
- Add tensor product elements (for tensor product cells)
- Add H(div) and H(curl) element-modifiers for TPEs
- Add enriched element, i.e. sum of elements (e.g. for building Mini)
- Add multidimensional taylor elements
- Add Gauss Lobatto Legendre elements
- Finding non-vanishing DoFs on a facets
- Add tensor product quadrature rule
- Make regression tests working again after few years
- Prune modules having only __main__ code including transform_morley, transform_hermite (ff86250820e2b18f7a0df471c97afa87207e9a7d)
- Remove newdubiner module (b3b120d40748961fdd0727a4e6c62450198d9647, reference removed by cb65a84ac639977b7be04962cc1351481ca66124)
- Switch from homebrew factorial/gamma to math module (wraps C std lib)