From 514299f40b7436b4d7ddb19d1e0a6f70d34dfa24 Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Mon, 30 Aug 2021 00:51:47 -0500
Subject: [PATCH] Add dcoll._base_to_geoderiv_connection
---
grudge/discretization.py | 62 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/grudge/discretization.py b/grudge/discretization.py
index 19b9230b..e84016c6 100644
--- a/grudge/discretization.py
+++ b/grudge/discretization.py
@@ -76,6 +76,10 @@ class DiscretizationCollection:
.. automethod:: nodes
.. automethod:: normal
+
+ .. rubric:: Internal functionality
+
+ .. automethod:: _base_to_geoderiv_connection
"""
# {{{ constructor
@@ -309,6 +313,64 @@ class DiscretizationCollection:
# }}}
+ # {{{ _base_to_geoderiv_connection
+
+ @memoize_method
+ def _has_affine_groups(self):
+ from modepy.shapes import Simplex
+ return any(
+ megrp.is_affine
+ and issubclass(megrp._modepy_shape_cls, Simplex)
+ for megrp in self._volume_discr.mesh.groups)
+
+ @memoize_method
+ def _base_to_geoderiv_connection(self, dd: DOFDesc):
+ r"""The "geometry derivatives" discretization for a given *dd* is
+ typically identical to the one returned by :meth:`discr_from_dd`,
+ however for affinely-mapped simplicial elements, it will use a
+ :math:`P^0` discretization having a single DOF per element.
+ As a result, :class:`~meshmode.dof_array.DOFArray`\ s on this
+ are broadcast-compatible with the discretizations returned by
+ :meth:`discr_from_dd`.
+
+ This is an internal function, not intended for use outside
+ :mod:`grudge`.
+ """
+ base_discr = self.discr_from_dd(dd)
+ if not self._has_affine_groups():
+ # no benefit to having another discretization that takes
+ # advantage of affine-ness
+ from meshmode.discretization.connection import \
+ IdentityDiscretizationConnection
+ return IdentityDiscretizationConnection(base_discr)
+
+ base_group_factory = self.group_factory_for_discretization_tag(
+ dd.discretization_tag)
+
+ def geo_group_factory(megrp, index):
+ from modepy.shapes import Simplex
+ from meshmode.discretization.poly_element import \
+ PolynomialEquidistantSimplexElementGroup
+ if megrp.is_affine and issubclass(megrp._modepy_shape_cls, Simplex):
+ return PolynomialEquidistantSimplexElementGroup(
+ megrp, order=0, index=index)
+ else:
+ return base_group_factory(megrp, index)
+
+ from meshmode.discretization import Discretization
+ geo_deriv_discr = Discretization(
+ self._setup_actx, base_discr.mesh,
+ geo_group_factory)
+
+ from meshmode.discretization.connection.same_mesh import \
+ make_same_mesh_connection
+ return make_same_mesh_connection(
+ self._setup_actx,
+ to_discr=geo_deriv_discr,
+ from_discr=base_discr)
+
+ # }}}
+
# {{{ connection_from_dds
@memoize_method
--
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