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 nodalityAdd
NodalEnrichedElement
which merges dual bases (nodes) of given elements and orthogonalizes basis for nodalityRestructuring
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)